What's Survivor Bias?

It's like survivor bias. You can't take a stock that exists to day because and trace it back ten years, because you have to look at the number of stocks available ten years ago. One thing that amazes me is silicon valley still, like many parts of silicon valley still haven't recovered from the docombum. And there's many places, like san jose, morgan hill, where housing prices are down, like 20, 30 % from their 19 99 price. Like that blows my freaking mind. Ye. Ind that wild.