Dow Closes at '09 High

(Updated with stock prices.)

NEW YORK (TheStreet) -- The Dow Jones Industrial Average closed at a new high for 2009 on Friday, amid a handful of expirations known to cause volatility.

Referred to as quadruple witching, contracts for stock index futures, stock index options, stock options and single stock futures all expired.

"You should see some volatility in the market, but normally the trend is positive on a day like today, especially if you open up positive in the morning," said Quincy Krosby, chief market strategist for Prudential Annuities. Statistically it should end on a positive note, she said.

Click below to hear my entire conversation with Krosby on quadruple witching, executive pay, earnings and the million-dollar-question -- where this market is headed.

The S&P 500 rose 2.81 points, or 0.3%, to 1068.30 -- that's more than 20% above the 200-day moving average, points out Linda Duessel, equity market strategist at Federated Investors. "It's very rare to be trading above that, particularly in a month that's historically weak, so to get above it might be a tough thing," says Deussel. But closing above the nearest resistance point could be bad for the bears as it lessens the odds for a pullback, she says.

With some help from an upgrade-inspired 3.2% gain in Procter & Gamble(PG Quote), the Dow Jones Industrial Average added 35.28 points, or 0.4%, to 9820.20. The Nasdaq Composite also increased 6.11 points, or 0.3%, to 2132.86.

Stocks posted the strongest weekly gains since July -- the Dow advanced 2.2%, and the S&P and Nasdaq tacked on 2.5% each -- suggesting again that the rally is durable. Still, observers are quick to point out overbought conditions as they question how long stocks can continue to advance.