This is just an idea I've had a few minutes ago while thinking about something different: What would happen if there was a mandatory "waiting period" for buying stocks, maybe 24h? Would that help to curb market instability and crashs? I mean technically speaking buying stock is supposed to be an investment, right? So why would you care so much whether you buy it now or tomorrow?
I'm not at all sold for that idea so far, because I'm not at all sure what unintended consequenes could arise. But at least in theory I imagine that there would be far fewer short-time mini bubbles and crashes. For example just yesterday between 8:25 and 8:55, the Netflix stock dropped from 323$ to 317$, that's 2%; just to then jump back to 324$ at 9:20. That's minutes determining whether somebody investing for his pension plan will have 200'000$ when he retires or 196'000$. Correct me if I'm wrong, but I think most of that fluctuation comes from people who see that the Netflix share is decreasing slightly, so they sell, hoping it goes even further, so that they buy again. As soon as it start increasing again, they buy again assuming that it's a low point and it will start growing for a considerable amount of time again. So increasing the time that it takes for the stock market to react to its current price, we would greatly reduce that level of "feedback loop", where the main reason why it's dropping is because it's already dropping.
If you imagine how it takes only up to a few seconds until the stock market has "reacted" to a slight decrease in price which means more people sell their stock, resulting in an even higher price decrease, etc. What if, because of the 24h waiting period, that time is 24h. It would take weeks and months for a significant drop in stock prices that isn't caused by some big news like that the company is going under. There'd be no point in betting on whether in 24h the price is higher or lower than right now, because that's essentially unpredictable. So a 24h waiting period would encourage only paying attention to how well the company is actually doing, because betting on the price to go up or down in the short run based on fluctuations because by the time your sale is complete the current trend may well have already been reversed a long time ago.
But since I literally just came up with the idea, as I said, I'm still quite skeptical, so what are some negative effects that I might have missed? Please tell me