[homologate]

Underwriters are not allowed to lend out shares for short sale until 30 days after the IPO. Other investors could lend out shares but there are not going to be that many shares on the market right after the IPO.

https://www.investopedia.com/ask/answers/05/062905.asp

[jdmichal]

If you want to short a stock, you get far better leverage with options than actual short positions. And AFAIK there's no limitations there.