US stocks reversed early gains on Thursday as investors paused to assess comments from JPMorgan (JPM) boss Jamie Dimon who warned about risks of a US stock market fall. Meanwhile, the FTSE 100 (^FTSE) and European stocks were mixed on the day.

Echoing the Bank of England on Wednesday, Dimon said he is “far more worried than others” about a serious market correction, which could come in the next six months to two years.

Speaking to the BBC, Dimon said a “lot of things out there” are creating an atmosphere of uncertainty, such as geopolitical risks, government spending, and the remilitarisation of the world.

“All these things cause a lot of issues that we don’t know how to answer. So I say the level of uncertainty should be higher in most people’s minds than what I would call normal.”

He added that he was concerned that the US stock market is overheated.

“People talk about stockpiling things like crypto, I always say we should be stockpiling bullets, guns and bombs. The world’s a much more dangerous place, and I’d rather have safety than not.”

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Elsewhere, traders are watching updates surrounding Israel and Hamas agreeing to pause fighting in Gaza so that the remaining hostages there can be freed in exchange for Palestinian prisoners.

Of the 251 people taken by Hamas on 7 October 2023, there are believed to be 48 hostages still being held in Gaza — 20 of whom are thought to be alive.

The Israeli government will meet on Thursday to approve the deal. If approved, the ceasefire will go into effect immediately.

Negotiations for the deal were held in Egypt, and aside from the Egyptian government, Qatar, the US and Turkey also helped broker the talks.

European Commission chief Ursula von der Leyen commended the diplomatic efforts to reach a deal, saying she is “encouraged” by the support given by the Israeli government and the Palestinian Authority. “Now, all parties must fully uphold the terms of the agreement,” she said.

Canadian prime minister Mark Carney said he is “relieved that the hostages will soon be reunited with their families. After years of intense suffering, peace finally feels attainable.”

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London’s benchmark index (^FTSE) was 0.3% lower by the end of the session, a day after hitting a new record. Housebuilders were hit by a survey from the Royal Institution of Chartered Surveyors that said Britain’s housing market lost momentum for a third consecutive month.

Germany’s DAX (^GDAXI) rose 0.3%, pushing to a fresh high, and the CAC (^FCHI) in Paris fell 0.1%

The pan-European STOXX 600 (^STOXX) was 0.3% down

The S&P 500 (^GSPC) slipped 0.3% on the day after another record close on Wednesday for the broad benchmark as Wall Street returned to rally mode. The Dow Jones Industrial Average (^DJI) also declined 0.3%, while the Nasdaq Composite (^IXIC) traded 0.4% lower.

The pound was 0.8% lower against the US dollar (GBPUSD=X) at 1.3300.