Initial public offerings (IPOs) often attract public interest, especially when familiar brands become available for the first time. There has been a long series of successful flotations such as the ride-hailing networks Uber and Lyft; workplace productivity services Zoom and Slack and other high-profile businesses ranging from Pinterest to Beyond Meats.

The media contributes to the frenzy around such flotations by building anticipation, tracking the early hours of trading and casting judgement on the IPO’s success. Investors can be lured by tales of outsize returns to try and get in early on the action.

Private IPO investors face some fundamental challenges when investing. They may not be able to trade during the early hours of flotation when the biggest price movements frequently occur.

Lockup periods often restrict when shares can be resold on secondary markets which can meaningfully limit the available liquidity in the first six to twelve months after the IPO. IPOs are commonly associated with outsized returns on the first day of trading but these returns may not be available to all investors. Researchers have shown that initial trading prices typically exceed the IPO offering price.

Accessing first-day returns requires an allocation from the underwriting banks. Studies document an adverse selection problem, finding allocations having poor first-day returns have generally been easier to obtain while allocations to IPOs with good first-day returns have usually been reserved for certain clients of the underwriting banks.

Medium-term performance of IPOs is often underwhelming. Research by Dimensional Fund Advisers Ltd., studied the first-year performance of 6,362 US IPOs from 1991 to 2018 and found they generally under-performed industry benchmarks.

From 1991 to 2000, there was a relatively high IPO rate of 420 per year but in the following 18 years, the rate of IPO fell to an average of 120 per year. Although IPO numbers declined, the average IPO size was almost three times larger than in the first 10 years. Most IPOs fall into the Small Cap group with 24% of IPOs in the Large Cap group and 19% in the Mid Cap group.