The stock market settled unchanged on Monday, as strength in financials offset weakness in consumer staples and telecom. The tech-heavy Nasdaq Composite handily outperformed the broader market with a gain of 0.8% thanks to strength in large-cap names.

Much of the action, however, was outside of the stock market, with crude prices going on massive $7 swing from peak to trough.

Crude oil futures soared 3.7% to an all-time high of $139.89 per barrel in premarket trading -- which occurred despite reports that Saudi Arabia is going to increase its output by 200,000 barrels a day, increasing worldwide supply by 0.2%. There was not a specific catalyst for the advance, although a declining dollar (-0.7%) and reports of a North Sea rig fire played a role in the buying interest. Then on no specific news, crude reversed in the red, settling the day with a loss of 0.8% at $133.82 per barrel.

The financial sector was once again in focus on Monday. Lehman Brothers (LEH 27.09, +1.28) reported a second quarter loss of $2.8 billion, or $5.14 per share -- matching its preannouncement. Lehman's stock rose 5%, with investors encouraged on word that the company cut its mortgage holdings by 20%.

AIG (AIG 34.02, -0.16) ousted its CEO in response to poor handling of the credit market turmoil, which follows in the footsteps of several other major financial firms. AIG said the management change is not in response to its second quarter results, which the company is expected to report sometime in August.

Financials (+1.1%) outperformed throughout the session, and settled the day with the largest advance.