The NASD warned on Friday that the tech dips were being bought on credit with margin money and that margin credit was reaching dangerous levels. According to the NASD there was $26 billion in margin debt on Nasdaq stocks in July which is the most current month reported. To put this in perspective there was only $21 billion in Nasdaq margin debt in March 2000 at the top of the market. Stocks bought on margin are considered held by weak hands as a sudden drop in the market can cause a wave of forced liquidation that further accelerates the drop. With Yahoo's market cap equal to General Motors there is concern that bubble mania has returned. Volume in low priced stocks has surged to more than the NYSE or Nasdaq. Volume in bulletin board stocks surged to 41 billion last month compared to 117 billion for all of 2000. This represents extreme speculation and an increase in market risk.