It hasn't had a true crash yet. In a real crash, volumes hit records, liquidity dries up, and trading becomes disorderly. This is *nothing* like Oct 87 (yet). In Oct 87 the cash/futures discount on the S&P was over 10% wide! In 9/11 bids *disappeared* in Europe (literally there was no bid). Trust me on this, if you have not experienced a crash you won't understand, but so far this has not got to that magnitude.
Most times the market bottoms without a real crash, so the fact one has happened does not mean it's a certainty we go lower (no certainties in the markets), but on some occasions they happen e.g. 87, 9/11/2001, especially when there are serious systemic risks as there are now. But I would not buy on the grounds that we've already "had a crash" because we haven't.
Looking at the price action, this is pretty dicey. That recent 990-1005 trading range just failed to the downside. Resistance now at 1020 and 1005 on the index, the only support is the opening low - that's the last hope for the bulls. If we break that, watch out.