A storm is blowing in from Trump's America and it could sweep Rachel Reeves away

Global share prices have been on a tear and the UK's FTSE 100 has been joining in, recently breaking 9,000 for the first time. That's a rare scrap of good news for Rachel Reeves, who is urging Britons to put more of their cash into shares rather than let it languish in savings accounts.

But the mood could soon turn. Bloomberg is warning that Wall Street big guns are preparing clients for a market meltdown as stock valuations rocket while the US economy slows.

Morgan Stanley reckons a correction of up to 10% is possible, while Evercore ISI is braced for as much as 15%. Deutsche Bank is also fearful.

Hedge fund manager Owen Lamont has dubbed August “panic season” and told investors to brace for an “epic financial disaster”.

The so-called Buffett indicator, a long-term measure of market value, is now at 207%. That's far above its historical comfort zone of 90% to 135%, suggesting shares are overpriced.

History shows that crashes often cluster between August and October. Many warnings prove false, but this time there's another problem – Donald Trump.

When Trump announced sweeping trade tariffs on April 2, shares plunged. But they flew to all-time highs after he paused them one week later.

Investors seem to think the worst is over, but Trump is cranking up the pressure. Levies on European goods are climbing to 15%. He's threatening 100% tariffs on semiconductors, vital to the artificial intelligence revolution, and 200% on pharmaceutical imports.

Trump hopes to reap billions from these measures but it will be the US economy that pays the price, as companies pass on the extra cost to consumers.

US jobs growth has now stalled, housing markets are weakening and mortgage applications are at 1990s lows.

Keir Starmer’s quick trade deal with Trump wasn’t perfect, but will shield the UK from the worst. But if the US stock market does crack Britain will still be hit – and Reeves will be in trouble.

The Chancellor already faces a £51billion black hole and will have to hike taxes again this autumn, even though it will slam growth.

A stock market crash would make her job even harder. It would slash capital gains tax and stamp duty from share trading, hit pension fund values, deter business investment and cut corporation tax receipts. A crash would also sap consumer spending and VAT revenues. All of this would put Reeves in an even deeper hole.

We may get lucky. Trump's latest tariff threats may be bluster. Any sell-off could be modest. Especially if the US Federal Reserve races to the rescue and slashes interest rates.

But with the UK’s finances on shaky foundations, despite Reeves's ridiculous claims to the contrary, even a minor tremor could bring them crashing down. Brace yourselves.