Believe it or not, the Dow Jones Industrial Average has rallied nearly 19% from its March 9 low. On Thursday, the index surpassed a 20% increase from that day, putting it in bull market mode. Still, not every market observer is convinced by the move, saying the coming week could expose the market's weaknesses once again. Profit-taking forced the Dow to give back nearly 2% during Friday's session. The day before, the blue-chip average closed at 7924.56, good for a 21% advance from the 12-year closing low of 6547.05 set on March 9. According to Dow Jones' public relations department, "technically, this would be considered a bull market." Paul Mendelsohn, chief investment officer with Windham Financial, isn't buying it. "We're in a bear market rally," Mendelsohn said. "I don't believe that the old standard of a bull or bear market measured by 20% moves works in this kind of environment. You're going to have rallies in a bear market. The only question is how far higher we'll go." Depending on who you ask, Mendelsohn is right in questioning whether a 20% move really is a true indicator of whether the stock market is in bull or bear mode, especially considering the Dow is down more than 40% from the October 2007 highs. James Paulsen, chief investment strategist with Wells Capital Management, agrees that a bull or bear market can no longer be defined by specific percentage moves. However, Paulsen does acknowledge that there are many positive signs that a bottom for stocks has been established.