> Either the price is higher than your bid, and your order won't fill (so why place it?) or the price is lower than your bid, and you should expect the market knows something you don't.

There is no risk-free way to trade. You can place a market order and guarantee execution, bearing the risk that you get a bad price. You can place a limit order, and guarantee price, bearing the risk that your trade doesn’t execute.

It sounds like you’re starting with the assumption that you don’t know whether the options are undervalued or overvalued, and if you start with that assumption, yes, the correct answer is don’t buy or sell the option (barring some other reason to buy or sell). Duh. But the reason the market “knows something you don’t” is because it’s full of people doing research. Sometimes, the person doing the research is you, and you have an idea of where the price will go. That’s what an edge is. When you have an edge, you can make money, but maybe not very much and not very reliably.

Where it gets ridiculous is when people speculate with SPY options or dumb shit like that. The reason why speculating with SPY is so ridiculous is because it’s just so unlikely that you could get an edge with SPY. But in general? Yes, it’s possible to get an edge.