So called "Liberation Day" and consequent mini-crash was on April 2, so this is just based on perception (of stupidity) rather than an anything real. No matter how well-grounded that perception is, the actual reaction to the tariffs is bound to be worse.
> Markets can react quickly, but this 0.3% stat is measuring GDP.
The GDP is the result of what markets (not the stock market, but actual markets for goods and services) do, if markets react quickly so does the GDP. And markets were reacting to tariff threats and other issues early in the term, Atlanta Fed GDPNow Q1 projection rapidly turned from strongly positive to negative in February, IIRC.
They both influence each other, yes. But GDP is largely a measure of consumer spending in the present, whereas stock markets are more forward-looking. Consumers, for the most part, respond to prices in the present. Savvy consumers have been stocking up in advance of anticipated price increases, and the less-savvy aren't really changing their spending yet because of stock buffers etc.