Naked shorting is legal for a certain number of days, based on...

Naked shorting is legal for a certain number of days, based on your position. A market maker for example has more days to borrow. I don't remember the exact number of days. Overstock.com and GameStop experienced situations where the number of shares shorted exceeded the number of shares available in the market, which is a significant indicator of naked short selling. and it required such a drastic situation to expose the naked shorting, because transparancy is insufficient. Still nobody was charged as far as I know. But you are right, it doesn't need to be 1/3. Could be 1/30 or zero. How where these extreme examples possible, if we had any meaningful transparency? Failure to deliver was not sufficient to detect it. Anyhow, forget about the naked short selling, it is not required for a short squeeze.