Cautionary tale:
A long time back, Chrysler was on the verge of bankruptcy and the stock was at pitiful levels. I bought a few hundred shares and watched the value of those shares triple or more when they bounced back.
Later, Pan Am was taking a similar beating. I bought a bunch of shares at $5, then more at $3. Turned around and it was down to $1 and change and hardly worth selling - who knows, it might come back. I held on as it went to zero. Lesson learned.
Point is, be careful out there with the falling knives. Every case is different.