A warden who oversaw a culture of abuse at two different federal prisons has a new job — running a national training academy for the Bureau of Prisons.

Andrew Ciolli was in charge of the penitentiary at Thomson in Illinois for one year before he moved to lead an even larger and more high-profile prison complex in Florence, Colo. An internal investigation by the Bureau of Prisons conducted last spring found that some staff at Florence used excessive force in violation of policy, and Ciolli, as warden, should have stopped it — but didn’t. Investigators referred him for disciplinary action. But he’s now landed a role as the director of the bureau’s Management and Specialty Training Center, which provides leadership training and specialized instruction across the agency.

“Historically, when a warden is disciplined for misconduct, they aren’t reassigned as a director of anything, let alone a training center,” said Thomas Bergami, who succeeded Ciolli as warden at Thomson before retiring last year.

Reporters reached out to Ciolli at a bureau email address for his new position. An unsigned response to that email declined to comment and referred reporters to the bureau’s Office of Public Affairs.

In a statement, Bureau of Prisons spokesperson Carl Bailey confirmed that Ciolli oversees the day-to-day operations at the training center, but said he “does not provide or oversee training.” Responsibility for the training “rests exclusively with subject matter experts, who operate independently of Mr. Ciolli’s oversight,” Bailey wrote.

He added that “allegations of employee misconduct are taken seriously,” and that the bureau “fully cooperates” with watchdog agencies “to bring to justice those who abuse the public trust.”

After a two-decade career rising through the ranks at the Bureau of Prisons, Ciolli became warden at Thomson in February 2021. An investigation by NPR and The Marshall Project exposed how during his tenure, three people were killed and dozens more alleged in lawsuits and interviews that they suffered serious mistreatment. Many incarcerated people described being shackled for hours or days at a time without access to food or a bathroom. The restraints were so tight, they often left scars on people’s wrists, stomachs and ankles that prisoners nicknamed the “Thomson tattoo.”

According to Bureau of Prisons policy, restraints should only be used on someone who is in immediate danger of hurting themselves or others or causing serious property damage. While staff can temporarily apply restraints, a warden must approve their continued use.

When Bergami took over the facility from Ciolli in 2022, he discovered an “enormous problem with inmate abuse,” he said in an interview last year. The Bureau of Prisons shut down a high-security unit at Thomson in 2023, citing “significant concerns with respect to institutional culture and compliance with BOP policies.”

In 2023, bureau Director Colette Peters testified before Congress that multiple Thomson staffers had been referred for administrative and criminal investigation for their roles in abusing prisoners. She did not name the employees. The bureau declined to comment on the status of those investigations.

After Ciolli left Thomson in 2022, Bureau of Prisons officials reassigned him to run the even bigger complex in Florence, with a $20,000 raise, according to the bureau. The job included overseeing a medium-security prison, a high-security penitentiary and the Supermax — which houses some of the country’s most notorious prisoners in single-cell solitary confinement.

A staffer at Florence becomes a whistleblower

But the recent federal investigation revealed that similar patterns of mistreatment found at Thomson, such as the excessive use of restraints, followed Ciolli to Florence. Last spring, a staffer at Florence who was tasked with investigating employee misconduct reported that officers were routinely using restraints on prisoners who did not meet the criteria for such treatment, according to a letter he wrote to federal officials. “All inmates were behind a secure door, no immediate threat to staff existed, and no actual disruptive behavior was observed from any inmate that would have placed a staff member in danger,” the whistleblower wrote to the U.S. Office of Special Counsel, an independent agency that handles such complaints.

The names of Ciolli and other Florence officials are redacted in investigative records obtained by NPR and The Marshall Project. But their job titles and descriptions are included, and two people with knowledge of the investigation confirmed their identities.

Investigators with the Bureau of Prisons’ Office of Internal Affairs reviewed video footage collected over nearly nine months at Florence penitentiary and found multiple instances of employees using force against prisoners who were “compliant, under control, and not a threat to staff or others,” according to a letter from the Office of Special Counsel to President Joe Biden.

Michael Antonio Thompson said he was restrained three times during the roughly 18 months he spent at Florence penitentiary, much of it while Ciolli was warden. Thompson was once left in cuffs for over 10 hours, he said. Officers “used to pepper spray me for nothing, hold me in chains for a whole bunch of hours,” he said in a phone interview. “Some people will put you in chains and put the handcuffs real tight until your hands turn blue and they swell up like baseball gloves.” He was released from prison in 2023.

Bailey, the bureau spokesperson, declined to comment on Thompson’s experience, for “privacy, safety and security reasons.”

The Bureau of Prisons’ internal investigation found the overuse of restraints at Florence was part of a broader program known as the High Visibility Watch Program, records from the whistleblower investigation show. The program targeted prisoners who were accused of masturbating in front of officers. Guards were instructed to fire pepper spray into their cells, force them into restraints and escort them to solitary confinement — whether or not they posed an immediate threat, investigators found. Those prisoners were then labeled with a yellow card around their neck.

These measures posed a “significant threat” to those in the program, the whistleblower wrote, “as inmates who engage in masturbation in a prison setting are prone to extortion, rape or assault from fellow inmates.” The Office of Internal Affairs found the program violated bureau policy, the office’s records show.

Several other employees moved from Thomson to Florence around the time of Ciolli’s departure in 2022, including Associate Warden David Altizer. According to the investigation by the bureau’s Office of Internal Affairs, staff members reported that Altizer and Ciolli called officers into a meeting after they arrived at Florence and instructed them to implement the watch program. The whistleblower told investigators that Altizer and Ciolli said “they had conducted a similar program at another location, and it was successful.”

When asked by investigators, Ciolli denied involvement and said he “could not remember” telling staff about the program, according to the bureau’s Office of Internal Affairs. Altizer was not interviewed in the inquiry, because he went on long-term medical leave shortly after the investigation began, according to documents from the investigation. Investigators concluded that at the very least, Ciolli was “responsible for providing managerial oversight and was accountable for determining policy” of the complex.

Altizer did not reply to requests for comment.

The whistleblower wrote in a separate letter to the Office of Special Counsel that a third official at the complex was involved in implementing the program. That person was cleared by the investigation and not referred for disciplinary action, and instead was promoted to warden of another prison complex.

This investigation was referred to several federal agencies, ultimately resulting in a report from the Office of Special Counsel to Biden explaining that most of the whistleblower’s allegations were true.

Both Altizer and Ciolli were referred for discipline, but neither was fired from the agency. Altizer retired in April. Ciolli began his new position with the training center in July, according to his LinkedIn profile and an internal bureau announcement. He lost his status as a senior executive in the agency and took a $3,350 pay cut, according to an email from the Bureau of Prisons.

After a string of scandals in the bureau, Congress has moved to increase oversight of the agency. This summer, Biden signed a law that would create a new ombudsman position in the Justice Department and require regular inspections of facilities with higher risk of mistreatment.

After the whistleblower report from Florence, the bureau also updated its use-of-force policy for the first time in a decade. It now explicitly states zero tolerance for excessive force, and that misconduct could result in criminal prosecution. It mandates de-escalation training and states that employees have an “affirmative duty to intervene” if they witness colleagues applying excessive force.

The policy now makes plain: Restraints may not be used for punishment, or “in any manner which restricts blood circulation” or “causes unnecessary physical pain or extreme discomfort.”

Christie Thompson and Beth Schwartzapfel report for The Marshall Project.

• Alabama
• Polls close at 8 p.m. E.T.
• Solid Rep.

Officials expect unofficial results to be available before noon Eastern time on Wednesday.

• Alaska
• Polls close at Midnight and 1 a.m. E.T.
• Solid Rep.

First results are expected around 1 a.m. Eastern time. Some absentee ballots will be counted late on election night, with subsequent counts taking place up to 15 days later. Ranked-choice voting is used in federal and state races; if no candidate receives at least 50 percent of the vote, the next tabulation will be conducted after 15 days.

• Arizona
• Polls close at 9 p.m. E.T.
• Tossup

First results typically come in around 10 p.m. Eastern time. Most voters cast ballots by mail, and counting typically takes days. Officials in Maricopa County, the state’s largest, said full tabulation could take 10 to 13 days.

• Arkansas
• Polls close at 8:30 p.m. E.T.
• Solid Rep.

Officials did not estimate how long counting would take, but most results are typically in by noon Eastern time on Wednesday. Only a small share of voters cast ballots by mail in the state.

• California
• Polls close at 11 p.m. E.T.
• Solid Dem.

Most voters cast votes by mail, and ballots can take days — or even weeks — to count. As of Friday, there were 6 House districts rated as tossups by the Cook Political Report. If the balance of power in the House comes down to these seats, it could be awhile before we know which party will take control.

• Colorado
• Polls close at 9 p.m. E.T.
• Solid Dem.

The state has long conducted its elections by mail. In 2020, it took about a day to report 95 percent of votes; in the 2022 midterms, it took almost four days. Much of the timing depends on how many ballots arrive on Election Day itself.

• Connecticut
• Polls close at 8 p.m. E.T.
• Solid Dem.

In 2022, most votes were reported by noon Wednesday, with 11 percent of voters casting ballots by mail (an excuse is required). The state has newly implemented early, in-person voting, but those ballots cannot be opened or tabulated until Election Day.

• Delaware
• Polls close at 8 p.m. E.T.
• Solid Dem.

Officials expect 100% of votes to be reported by midnight on election night.

• District of Columbia
• Polls close at 8 p.m. E.T.
• Solid Dem.

In 2020, about 69 percent of votes were reported by noon Wednesday; in 2022, that share was 80 percent. Each registered voter was mailed a ballot, which has 10 days to arrive if postmarked by Election Day.

• Florida
• Polls close at 7 p.m. and 8 p.m. E.T.
• Likely Rep.

Votes are counted extremely quickly, with 99 percent of votes reported by midnight in both recent general elections. First votes are expected after most polls close at 7 p.m. Eastern time.

• Georgia
• Polls close at 7 p.m. E.T.
• Tossup

Most voters tend to vote early in person, and vote reporting is usually relatively fast. The share of ballots cast by mail is expected to be much smaller than in 2020, but the state could still be counting corrected mail ballots, overseas and provisional ballots for several days.

• Hawaii
• Polls close at Midnight E.T.
• Solid Dem.

The state runs a predominantly mail election. In 2020, it took until about 7 a.m. Eastern time on Wednesday to reach 95 percent of votes. In 2022, it took an additional day.

• Idaho
• Polls close at 10 p.m. and 11 p.m. E.T.
• Solid Rep.

Officials said they would not expect this election to be much different than previous ones, though 2020 was probably an outlier. In 2020 and 2022, most results were reported by noon Eastern time on Wednesday. First results are expected after 11 p.m. Eastern time.

• Illinois
• Polls close at 8 p.m. E.T.
• Solid Dem.

Officials said that reporting could look similar to 2022, when more than 90 percent of votes were reported by noon Eastern time on Wednesday. Ballots postmarked by Election Day have two weeks to arrive, but most jurisdictions should have their complete unofficial results within a week.

• Indiana
• Polls close at 6 p.m. and 7 p.m. E.T.
• Solid Rep.

In 2022, most ballots were counted by noon Eastern time on Wednesday. A smaller share of voters cast mail ballots that year compared with 2020, and requirements for doing so have become stricter since. First results are expected after polls close in most of the state at 6 p.m. Eastern time.

• Iowa
• Polls close at 9 p.m. E.T.
• Solid Rep.

In 2022, after the poll closing time was moved one hour earlier, 95 percent of votes were reported by midnight Eastern time. Mail voting rates have fallen since 2020, when absentee ballot request forms were mailed to every eligible voter.

• Kansas
• Polls close at 8 p.m. and 9 p.m. E.T.
• Solid Rep.

Most votes were reported by noon Eastern time on Wednesday in 2020 and 2022. Ballots cast by mail, which have three days to arrive if postmarked by Election Day, have been used less than in 2020.

• Kentucky
• Polls close at 6 p.m. and 7 p.m. E.T.
• Solid Rep.

Officials said they hope to report unofficial results by midnight Eastern time on election night.

• Louisiana
• Polls close at 9 p.m. E.T.
• Solid Rep.

Officials expect that unofficial votes will be counted before noon Eastern time on Wednesday. In the state’s open primary system, which is used in nonpresidential races, if no candidate wins a majority of the vote, the top two vote-getters advance to the next election on Dec. 7.

• Maine
• Polls close at 8 p.m. E.T.
• Likely Dem. Maine statewide
  Solid Dem. Maine 1st
  Likely Rep. Maine 2nd

Officials said they expect a pace of reporting similar to 2020, when most results were in by noon the next day. In races where ranked-choice voting is used, including for the presidency and U.S. Congress, only first rankings will be available; if no candidate receives a majority, a second tabulation will occur in the days following the election.

• Maryland
• Polls close at 8 p.m. E.T.
• Solid Dem.

Officials said they had no reason to think the pace of reporting would differ from 2020 and 2022, when more than 70 percent of votes were reported by noon on Wednesday. Postmarked mail ballots that arrive on Election Day or after will be counted starting two days after the election.

• Massachusetts
• Polls close at 8 p.m. E.T.
• Solid Dem.

In both 2020 and 2022, more than 90 percent of votes were counted by noon on Wednesday, with more than one-third of voters casting a ballot by mail. Ballots postmarked by Election Day have three days to arrive.

• Michigan
• Polls close at 8 p.m. and 9 p.m. E.T.
• Tossup

Most votes are generally in by noon Eastern time on the day after the election, and the state has passed reforms that could contribute to faster counting. In 2020, Mr. Biden ultimately won Michigan, but a “red mirage” showed Mr. Trump ahead in the reported tally before all mail ballots had been counted. It is unclear how new rules will affect the order of votes reported this year.

• Minnesota
• Polls close at 9 p.m. E.T.
• Likely Dem.

Officials say it’s possible that more counties will report results after midnight Eastern time this year. While officials are now allowed to start processing mail ballots sooner, the absentee ballot deadline has moved to 9 p.m. Eastern time from 4 p.m., which could contribute to the slightly later results.

• Mississippi
• Polls close at 8 p.m. E.T.
• Solid Rep.

Officials said they had no reason to think reporting would differ from recent major elections, when between 80 and 90 percent votes were counted by noon on Wednesday.

• Missouri
• Polls close at 8 p.m. E.T.
• Solid Rep.

Officials said that most counties should report at similar rates to recent general elections, when unofficial results were reported by noon Eastern time on Wednesday.

• Montana
• Polls close at 10 p.m. E.T.
• Solid Rep.

Most voters cast ballots by mail, which must be received by Election Day. More than 90 percent of votes have been reported by noon Eastern time on Wednesday in recent major elections.

• Nebraska
• Polls close at 9 p.m. E.T.
• Solid Rep. Neb. statewide
  Solid Rep. Neb. 1st
  Lean Dem. Neb. 2nd
  Solid Rep. Neb. 3rd

Officials expect reporting to follow the same trend as recent elections, with most votes counted by noon Eastern time on Wednesday. A new voter ID law could result in more voters casting provisional ballots, which take longer to be processed.

• Nevada
• Polls close at 10 p.m. E.T.
• Tossup

About half of voters usually cast ballots by mail, and counting usually takes days. It could be faster than in the past because of new technology and a rule that allows officials to tabulate ballots sooner. Postmarked ballots are allowed to arrive up to four days after the election, on Nov. 9.

• New Hampshire
• Polls close at 7 p.m., 7:30 p.m. and 8 p.m. E.T.
• Likely Dem.

With the exception of Dixville Notch — the small town that begins voting at 12 a.m. on Election Day and promptly reported five votes in 2020 — vote counting in the state has extended into the day after the election.

• New Jersey
• Polls close at 8 p.m. E.T.
• Solid Dem.

The state introduced early in-person voting in 2021, and mail voting has dropped significantly from its 2020 levels. In 2022, about 90 percent of ballots in U.S. congressional races (not shown) had been counted by noon the day after the election.

• New Mexico
• Polls close at 9 p.m. E.T.
• Likely Dem.

In the last two general elections, nearly all unofficial results were reported by noon Eastern time on Wednesday. By 1 a.m. Eastern time on Wednesday, processing of absentee ballots must either conclude, or pause and resume the next day.

• New York
• Polls close at 9 p.m. E.T.
• Solid Dem.

State officials would not comment on timing, but there have been some recent changes that could affect results reporting. Mail ballots, which must be postmarked by Election Day but are allowed to arrive up to a week later, no longer require an excuse. In 2020, no mail ballots were counted until after election night, but that changed for 2022.

• North Carolina
• Polls close at 7:30 p.m. E.T.
• Tossup

Early, in-person voting is very popular, and votes are typically counted very quickly, with nearly all votes reported by midnight. New rules mean that early voting results will no longer be reported immediately at poll close time, but mail ballots are now due on Election Day (in 2020, ballots postmarked by Election Day had nine days to arrive).

In 25 western counties affected most by Hurricane Helene at the end of September, voters have been given special accommodations for casting their ballots, and a small number of secure tents have been erected to replace destroyed polling sites.

• North Dakota
• Polls close at 8 p.m. and 9 p.m. E.T.
• Solid Rep.

In the past two general elections, unofficial results were reported by noon Eastern time on Wednesday. Ballots must be postmarked by the day before the election, but those arriving after Election Day will not be counted until about two weeks after the election.

• Ohio
• Polls close at 7:30 p.m. E.T.
• Solid Rep.

Most votes tend to be reported on election night. Like in many other states, mail voting rates fell in 2022. Mail and early in-person votes favoring Democrats tend to be reported first.

• Oklahoma
• Polls close at 8 p.m. E.T.
• Solid Rep.

In recent general elections, nearly all votes have been reported by midnight Eastern time on election night.

• Oregon
• Polls close at 11 p.m. E.T.
• Solid Dem.

Officials said counting the unofficial results would take a few days. The state, which conducts all-mail elections, passed a new law in 2021 allowing ballots postmarked by Election Day to arrive up to seven days later.

• Pennsylvania
• Polls close at 8 p.m. E.T.
• Tossup

Counting is expected to extend beyond election night, primarily because election workers are not allowed to start processing mail ballots until Election Day. Still, vote counting could be faster than in 2020, partly because of new, faster equipment and ballot counting requirements. In 2020, after an initial batch of heavily Democratic votes, the reported tally favored Mr. Trump until more mail ballots were counted, and Mr. Biden’s margins increased.

• Rhode Island
• Polls close at 8 p.m. E.T.
• Solid Dem.

Officials said vote counting should look similar to 2022, when 99 percent of votes were counted by midnight on election night.

• South Carolina
• Polls close at 7 p.m. E.T.
• Solid Rep.

Officials said they expected most votes to be reported by noon on Wednesday.

• South Dakota
• Polls close at 8 p.m. and 9 p.m. E.T.
• Solid Rep.

In recent general elections, about a quarter of voters cast ballots by mail, and between 90 and 100 percent of votes were reported by noon Eastern time on Wednesday. First results are expected after 9 p.m. Eastern time, when the last polls close in the state.

• Tennessee
• Polls close at 8 p.m. E.T.
• Solid Rep.

Full, or nearly full, results have been reported by midnight Eastern time in recent general elections.

• Texas
• Polls close at 8 p.m. and 9 p.m. E.T.
• Likely Rep.

Most votes tend to be counted on election night. Voting by mail requires a valid excuse, and only a small share of voters cast ballots this way. First results are expected when polls close in most of the state, at 8 p.m. Eastern.

• Utah
• Polls close at 10 p.m. E.T.
• Solid Rep.

Most voters cast ballots by mail, and officials say the timing of results will largely depend on how many ballots are returned at the last minute. Ballots postmarked by the day before the election have two weeks to arrive.

• Vermont
• Polls close at 7 p.m. E.T.
• Solid Dem.

Officials said they had no reason to think the pace of reporting would differ from 2020 and 2022, when nearly all votes were reported by noon on Wednesday.

• Virginia
• Polls close at 7 p.m. E.T.
• Likely Dem.

Most results tend to be reported by noon on Wednesday, though mail ballots postmarked by Election Day have three days to arrive. The share of voters casting a ballot by mail fell to about 9 percent in 2022 from 22 percent in 2020.

• Washington
• Polls close at 11 p.m. E.T.
• Solid Dem.

Officials expect full, unofficial results five to seven days after the election (though postmarked ballots have 20 days to arrive). Much of the timing depends on how many ballots are returned early.

• West Virginia
• Polls close at 7:30 p.m. E.T.
• Solid Rep.

Nearly all unofficial results tend to be reported by noon on Wednesday. Officials say they have no reason to think this year will be different.

• Wisconsin
• Polls close at 9 p.m. E.T.
• Tossup

Complete unofficial results are not expected until the morning after the election. Officials cannot begin processing ballots until Election Day, but they are required to count through the night. In some places, absentee ballots are counted at a central facility and are reported in large batches. In 2020, a “red mirage” showed Mr. Trump ahead in the reported vote until the final results arrived. That pattern did not repeat in 2022.

• Wyoming
• Polls close at 9 p.m. E.T.
• Solid Rep.

All unofficial results were reported by noon on Wednesday in 2020 and 2022. Officials say they have no reason to think this year will be different.

Big Tech’s capital spending is on track to surpass $200bn this year and rise even further in 2025, as anxiety grows on Wall Street about the returns on soaring investment in artificial intelligence.

The four biggest US internet groups — Microsoft, Meta, Amazon and Google’s parent Alphabet — this week offered investors brief glimpses into the benefits they are seeing from their headlong rush into generative AI, arguing that it was boosting the performance of core services and helping to hold down operating costs.

But the stock market suffered a spasm on Thursday as investors looked past the imprecise benefits to focus instead on another big — and very measurable — jump in spending on chips and data centre infrastructure, as the AI race accelerates.

Capital expenditure at the four biggest hyperscalers grew more than 62 per cent on the year before, to about $60bn during the quarter, according to this week’s financial reports. Meta and Amazon were among those to point to further increases in spending next year.

Analysts at Citi forecast that the quartet’s total capital spending will hit $209bn this year, up 42 per cent on 2023. Citi estimates that data centres account for about 80 per cent of that total.

“What is the real benefit?” said Jim Tierney, a growth stock investor at AllianceBernstein, voicing a common concern. “All of these companies are spending a huge amount of money,” he added, with a resulting hit to profit margins that would become “more noticeable in 2025”.

One sign that demand for generative AI was starting to lift Big Tech’s growth rates came from the accelerating growth in the cloud divisions at Microsoft and Google.

But the optimism quickly dissipated when Microsoft went on to warn that cloud growth would slip back this quarter, largely because of supply constraints. Meanwhile, cloud market leader Amazon Web Services failed to hit the most optimistic hopes for an acceleration in its own growth, even as it lifted investors’ spirits with unexpectedly strong profit margins.

Companies that peppered their earnings calls this week with anecdotal and mostly vague assurances about AI returns included Alphabet, which said the new generative AI features in its search engine were increasing engagement and boosting usage. It also said a quarter of the software it produced was now written by AI.

Despite this, the growth in Google’ search volumes declined from the preceding quarter, said Tierney, raising a question about how strong the AI effect had been.

However, Microsoft said its revenue from AI was on the brink of hitting an annualised $10bn, reaching that milestone faster than any other business in its history. It also said that Copilot — an AI feature for which it charges a monthly fee of $30 per user — had experienced “the fastest growth of a new suite” yet seen in its M365 productivity software.

The $10bn figure was a rare disclosure of a hard revenue number and serves as an early proof-point of the real benefits that could start to flow from generative AI, said Brent Thill, an analyst at Jefferies.

But few other software companies have revealed anything about the effects of AI on their revenue, he added, leaving the stock market to fret. “It’s murky. And investors are freaking out about the costs,” Thill said.

For its part, Meta told investors that AI had boosted returns from its advertising and improved engagement among users, while AWS said its “multibillion-dollar” AI business was growing at a rate of more than 100 per cent.

If anecdotes like this were encouraging but fuzzy, the rapidly rising spending on new data centres and equipment for AI was all too clear.

Facing a grilling from investors, executives at several companies claimed the massive increase in facilities to handle AI was closely tied to demand, and that capital efficiency would improve as the business increased in scale.

Executives at Amazon and Microsoft drew comparisons with the early days of the cloud computing business, when building and equipping fleets of data centres also caused spending to soar.

There are strong advanced buying signals from customers that make it possible to time investment spending closely to actual demand, said Amazon’s chief executive Andy Jassy. Microsoft’s chief financial officer Amy Hood said about half of the software company’s capital spending goes on server purchases, which could be timed closely to increases in demand.

Despite the claims of investment discipline, investors were left with the reality that the higher spending will hit Big Tech’s income statements next year, even as any revenue benefits are uncertain.

Meta, for instance, warned that 2025 would see “significant acceleration in infrastructure expense growth”, as its new fleet of data centres lead to higher depreciation charges and operating costs.

Changes in depreciation policies at Microsoft, Alphabet and Amazon in recent years will lessen the pain. All three have extended the useful lives of their data centre gear for accounting purposes, reducing the amount of depreciation they need to report each year.

Amazon said extending the useful lives of its servers by a year had lifted the profit margin in its cloud division by 2 percentage points in the latest quarter — the second time it has taken this step in two years.

But even after the moves to push depreciation charges further into the future, the pressure on margins from soaring spending on AI will be hard to avoid.

After a powerful two-year rally as earnings expectations for Big Tech have ratcheted steadily higher, this could indicate a turning point. The tech-heavy Nasdaq Composite closed 2.8 per cent lower on Thursday, with Microsoft, Meta and AI chipmaker Nvidia together shedding more than $400bn in value.

On Friday morning, shares in Meta and Alphabet were broadly flat, while Microsoft and Amazon were up, at 1 per cent and 7 per cent, respectively. Nvidia rose 3 per cent.

“Investors are left asking if the ‘beat and raise’ era [in quarterly earnings announcements] is over,” said Tierney. If so, the convulsion that passed through the market on Thursday could be a sign of rockier times ahead.