Which of the following statements regarding IPOs is correct?

A. IPO firms are required to hire investment banks as underwriters before registering with the SEC.

B. Flipping means institutional investors sell shares back to the secondary market.

C. Short-run underpricing means that the first day closing price, on average, is lower than the offer price.

D. IPO firms tend to perform better in the long run in the hot market than in the cold market