Hi can you please help me with this question:

1. On August 19, 2004, the Internet search firm Google went public, at an offer price of $85 per share. The IPO was unconventional in that Google used an auction to determine its offer price and sell shares to investors. In this respect, underwriters did not allocate shares to clients. Instead investors registered to participate in the auction, and indicated the maximum price they were willing to pay, along with the number of shares they wished to purchase. If a registered investors maximum price was at least the offer price, the investor paid the offer price, not their maximum price. Google had established its initial file range for the offer price to be $108 to $135 a share. However, based on the interest shown by investors in registering for the auction, the firms executives reduced the range to between $85 and $95. On its first day, Google stock opened at $100 per share. Were investors who purchased Google shares at $100 irrational, in that they could have paid $85 the day before? Or might there be some other explanation for the 17 percent jump in price when the stock began to trade publicly? Discuss.