NEW YORK (TheStreet) - At least for one day, investors are erasing any bearish thoughts they've had in the past few weeks, as the S&P 500 climbs 1.2% on Monday. 

Warren Buffett's BerkshireHathaway (BRK.A) - Get Report buying Precision Castparts (PCP) for $37.2 billion is certainly helping improve investors' moods, said Stephanie Link, portfolio manager at TIAA-CREF, on CNBC's "Fast Money Halftime Report." 

M&A is now up 51% on the year compared with last year, Link added. This shows that managers are confident in the economy and still see value in stock prices, she noted. She recommended investors watch for this week's release of retail sales data, which will be an important indicator for consumption. 

While Monday's price action is nice, stocks are still stuck in a range, pointed out Pete Najarian, co-founder of and However, financials, health care and the S&P 500 have all held key support levels, Najarian said, calling that a good sign. 

And although stocks are rising on the day, Josh Brown, CEO and co-founder of Ritholtz Wealth Management, said he's not jumping on the bullish bandwagon just yet. The leaders -- energy, materials and industrials -- have been this year's worst performers and this seems like nothing more than a temporary bounce. 

Maybe the catalyst to get stocks to break out above this range is the dreaded rate hike from the Federal Reserve, Brown said. If the Fed raises rates in September, stocks will likely see at least some downward pressure. But as soon as investors realize the economy is still going strong and the world isn't ending, they may let out a huge sigh of relief and go back to buying stocks, he said.

Joseph Terranova, senior managing partner at Virtus Investment Partners, added that companies can resume buying back their stock now that the blackout period surrounding earnings is over. It's worked over the past four quarters, so there's little reason to believe stocks won't see a rise this time around too, he said.

Focusing on energy, crude oil is up 2% on the day, approaching $45 per barrel. However, John Kilduff, founding partner at Again Capital, said he expects more downside pressure on the commodity. Oil will probably bottom in the low $30s by September or October, he predicted.

Saudi Arabia continues to produce a lot of oil, hurting non-OPEC producers. At some point, Exxon Mobil (XOM) - Get Report, Chevron (CVX) - Get Report and ConocoPhillips (COP) - Get Report will be buys, but not right now, Kilduff said. 

Link said she likes high-quality oil exploration and production (E&P) stocks and finds the majors attractive when the dividend yields climb to 4.5% to 5%. 

The conversation turned to Apple (AAPL) - Get Report, as shares of the tech giant rallied 3.5% on Monday. 

Andrew Uerkwitz, an analyst at Oppenheimer, says he remains bullish on Apple, and thinks the recent selloff is simply an overreaction.

Investors are connecting the dots between China's weakening economy and Apple's iPhone sales, concluding that the latter must be suffering from the former, he said. That's not necessarily the case, and Apple still has "plenty of room to go in China," he said, adding that people seem to be looking for reasons to not like the stock.

Najarian agreed that the selloff is unjustified. It doesn't help that investors have been waiting for a correction in stocks and may have been taking profits in Apple as a way to lock in gains.

Part of the move was technical, with shares breaking below the 200-day moving average, Terranova said, but he attributed Apple's sell-off in large part to concern over Chinese consumers. Still, he doesn't believe the story for Apple is over.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.