This document presents conjectures about the causes of the dotcom bubble and high underpricing of IPOs during 1999-2000. It proposes two main conjectures: 1) The large inflow of high-growth IPOs affected expectations about long-term growth rates in the industry, feeding the price spiral in the stock market. 2) Some companies strategically underpriced their IPOs to avoid risks associated with distributing overvalued shares, as they needed continued access to capital markets for acquisitions or future funding rounds. The document provides evidence that the flow of high-growth IPOs explains returns in the NASDAQ index, and that characteristics like pre-IPO acquisitions can fully account for the high