In general the reason a lot of stocks go up or down unexpectedly is due to options. For example Friday with AMZN the stock dropped a lot towards the end as people who really shouldn't even be involved with such an expensive stock had loaded up on calls the day before or that week and were now dumping as their gamble failed.

And yes, 90% of options expire worthless.

For years now I have stuck to the actual stock only both in long term and in investing. This way if things go against you, you have time on your side, versus with options time is decidedly against you as their value decays even if the stock moves in your favor, until that ultimate judgment day when if you're not sufficiently in the money you lose irrevocably.