<human>:  What's the difference between an IPO and a secondary offering?
<bot>: The main difference between an Initial Public Offering (IPO) and a Secondary Offering is the source of the securities being offered. An IPO is when a company issues new securities to the public in order to raise capital, while a Secondary Offering is when the company issues existing securities that have already been issued and are currently owned by an investor or the company itself. In an IPO, the new securities are sold to the public, while in a Secondary Offering, the existing securities are sold by the current shareholders to the public.