Wall Street hit a record high, but it could be a signal of bad things to come.
In 1995, mathematician Jim Miekka coined a phrase for an economic indicator that could signal a recession.
Named for the doomed zeppelin, the Hindenburg Omen is supposedly triggered right before a stock market crash.
And on the New York Stock Exchange and the Nasdaq overnight on Friday, the Hindenburg Omen was triggered simultaneously.
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The indicator is when one side of the stock market is soaring while others are at record lows, AMP Economist My Bui told nine.com.au.
"If the economy is running well, then most of the components, or most of the stocks that are making up the index should actually all go up," Bui said.
"Else it might not be a sustainable rise."
Right now AI companies and other technology businesses are doing incredibly well on Wall Street.
Meanwhile, health care and telecommunications are struggling.
Right now the US share market is surging while consumer confidence is at a record low - a trend economists don't believe to be sustainable.
But the Hindenburg Omen is far from a guaranteed indicator of a looming crash.
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While it has predicted just about every Wall Street crash in the past few decades, it has also forecast dozens more crashes that never happened.
The omen would have been triggered 69 times since 1965 - and there have not been 69 stock market crashes since then.
Brokers have been unfazed by the omen being triggered this time around.
The S&P 500 Index hit a new record high overnight, up nearly 57 points.
So what are the chances of a stock market crash?
"It's never zero, and I do think it's higher than the historical average," Bui said.
"But I think that if there's a big decline in shares, like, say, 10 per cent or more, then Trump would do something substantial to boost it up again."
The ASX200 has followed Wall Street up this morning.
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