The risk is real, but many people are risk averse enough to be prepared to take a small loss [or lesser profit] to avoid risk of a bigger loss in basically ever

The risk is real, but many people are risk averse enough to be prepared to take a small loss [or lesser profit] to avoid risk of a bigger loss in basically every market anywhere - that's why insurance is a thing! And you could see an effect in some individual stocks of traders whose strategies rely on reacting to stuff fast allowing traders whose strategies don't to profit by risking holding onto the stock for at least several hours, even if the average effect was zero because a few other stocks did have bad news overnight giving the bagholders of those stocks big losses...