The stock market is chaos, driven by bias and a bunch of unknown and unknowable variables.

A simple example with 3 players.

• P1 thinks stock A is a good buy (for whatever reason) at $1/unit. P1 decides to buy putting upward pressure on the price.
• P2 has been holding a bunch of A for a while and has a number ($1) in mind to sell at, P1 can't know this information. This sale puts downward pressure on the price.
• If P1 & P2 have the same number of shares, the pressures are equal, and the price doesn't move. If they don't the price moves either up or down.
• P3 has been watching A, sees that it moves and decides that this is a good time to buy, (going down its a bargain, going up its on the rise get in early), putting further upward pressure on the stock.

Each action by the different players causes something to happen to the price, no-one can know all the internal thought patterns of all the other interested parties, and thus can never have perfect information. And even with perfect information, it may not be possible to predict, as some stocks interact in non-predictable ways.

e.g. Nvidia goes up, TSMC usually goes up, but not always. TSMC going down can be caused by Nvidia, but also thousands of other things also.

Conclusion: can the stock market be predicted? General trends - Yes, specific stock movements - No!