Not since Bill Gates took Microsoft public in 1986 has Wall Street witnessed anything like the wealth-creating power of today's Internet stocks. Consider Amazon.com an online bookseller that has lost more than $30 million since 1995 with nary a penny of profit in sight. No matter. Amazon's $5 billion in market value exceeds the combined capitalization of Barnes & Noble and Borders Group, the two largest U.S. bookstore chains. The rise of No. 1 search engine Yahoo has been no less phenomenal. It stood at $181 a share last week after reporting second-quarter earnings of $8.1 million--following three straight years of...

