This isn't how I see it at all. In my view, there's a price that correctly prices in all information that's knowable. Note that each individual may have his ow

This isn't how I see it at all. In my view, there's a price that correctly prices in all information that's knowable. Note that each individual may have his own version of this price, which is why buying and selling takes place. "Market efficiency" just means if I think it's worth 5 and you think it's worth 10, and we're participating equally in the market, the price will be 7.5. It does not mean one of us is necessarily not right and the other not wrong. If the market price is 7, but I have better information that makes be believe it's worth 10, I'm right, the market is wrong. Efficiency just means everything is aggregated properly and all opinions are priced in. In the long term, we all know stocks are driven by both macro and company fundamentals, stuff like GDP growth, earnings, margins, revenue, free cash, etc. But there's also a short-term view that drives prices day-to-day. I think Peter Lynch was right, that short-term movements are more like a "voting machine" driven by news, hype, perception, and a lot of other things. While short-term pricing is unpredictable, I don't think it can properly be called "random" in the sense of a coin toss, or dice roll. It may be hard to predict, but it does feel that there's a definite cause and effect to things. In the case of Tesla, you may not know that they were going to release news of a crash, but it's a pretty safe bet that once that news is released, it's going to depress prices. It's not hard to see why, market participants are human, they do things for reasons, though those reasons may not be well-informed, predictable, or otherwise rational. What's interesting is how these two views--the short and long-term ones--equilibriate/converge over time. Empirically, I've observed it's usually some sort of "event", whether an earnings release, or a news item, or a job report, that causes this equilibriation process to kick off. All of a sudden, some good or bad news item breaks, and the market "overreacts" (positively or negatively). I find this really interesting.