With the stock market going through the ups and downs that it's going through and with Warren Buffet saying "now's the time to be greedy" when it comes to stocks, several people have asked me which tech stocks might be a good buy. In my 20s, I caused several people to lose money based on bad stock advice and never gave anyone advice again. I still don't. But I poked around anyway and discovered that on Thursday, Oct. 23, four major tech brands hit their 52-week lows and others came very close. How often does that happen?According to the investment sites, Amazon hit a 52-week low of 43.31 today (the 52-week range was 43.31 - 97.43). Sun hit a low of 4.32 (its range was 4.32 - 24.08). EMC hit its 52-week low of 9.00 (with a range of 9.00 - 25.47). Salesforce.com went as low as 25.69 (its range was 25.69 - 75.21). Four tech titans. Four Wall Street lows in one day.

And then there were some runners up. At 20.89 with a 52-week range of 20.65 - 37.50, Microsoft came within 25 cents of hitting a new bottom, and Yahoo, which struck 11.55, missed a new low by 19 cents. It's range is 11.37 - 34.08. Big Blue? IBM dipped to $81.00 today, missing a new 52-week low of 80.80 by 21 cents. Then there was Dell. At a daily low of 11.49, Dell missed its new 52-week low of 11.47 by just a few pennies. Whoa.

And these were the only stocks I checked (OK, I checked one other -- HP, which isn't trading near its low). What was yesterday, Tech's Black Thursday?

OK, next question. Is it time to buy?