Try Quandl. It has info on startups and venture capital, you might find IPO info in there or a link to what you want.
This is Quandl's data collection on US startups, entrepreneurship, angel investments and venture capital.
Quandl's startup data includes number of investments, investment size, and valuation data at each stage of the startup financing pipeline: seed and angel investments, early-stage venture capital including Series A, late-stage venture capital and growth equity, and exits including IPOs and acquisitions. The data is organized by time across different sectors, stages and states.
Source for Quandl's data on entrepreneurship, angel investing and venture capital in the USA include the Bureau of Labor Statistics, the National Venture Capital Association, the Center for Venture Research, the Cooley Venture Financing Report, the Kauffman Foundation, and Crunchbase.
Click on any indicator name or graph to see a full, freely-downloadable historical time series of that data. All datasets on Quandl are also available via our free and unrestricted API.