In the early days of the 2008 financial crisis, there was actually a lack of liquidity. In the case of insufficient liquidity, even the currency with shrinking liquidity will lead to further insufficient liquidity. Without liquidity to support safe-haven assets, it is difficult for prices to rise, and liquidity will shrink further, which will make people who hold safe-haven assets sell their assets in exchange for liquidity. In a market dominated by selling assets, their asset prices are bound to fall. Then with the recovery and increase of liquidity, asset prices began to rise.

It is hard to say whether you can invest before the financial crisis. After all, it is also an asset. The situation is different and cannot be generalized. If you must invest, don't invest all your money at once, just pay attention to controlling risks.