[perl4ever]

There are some specific reasons:

1. The US Fed has started a tightening cycle, and we've seen them repeatedly overshoot in the past, causing a correction or recession. Simply based on recent patterns, one might expect something to happen once short term rates get to, say, 4-5%.

2. The US President is demanding mutually exclusive things from the economy, fomenting trade wars, and attacking the independence of the Fed, which may have negative consequences.

3. The US stock market is valued more highly relative to normalized earnings than it is usually, or the rest of the world is now.

4. US Federal budget deficits are dramatically worsening. Republicans are only deficit hawks when there is a Democratic president. It's been so long since we've had real inflation that it could really shock people, and per point (2) the President appears to want low rates at the expense of inflation (at least today - who knows tomorrow).