NEW YORK (TheStreet) -- The Dow Jones Industrial Average is set to have its worst month since 2010, falling 6.5% in August. Despite the drop, not all investors have been turned into bears. 

Last week, Tony Dwyer, chief U.S. strategist at Canaccord Genuity, issued his "all-in" report. On Monday's CNBC's "Fast Money Halftime" show, Dwyer reiterated his year-end price target of 2,340 for the S&P 500

Dwyer said volatility is likely to stay high for the next few months, and he acknowledged that stocks could ultimately retest recent lows. But that would be a buying opportunity, he said. Once the Federal Reserve raises interest rates, it could create a buying catalyst when it dawns on investors that the move really isn't all that bad. 

The conversation then turned to oil, as the commodity is surging 7% on Monday. Oil is up a whopping 26% over the past five days. Investors seem to be turning more optimistic that perhaps the Organization of Petroleum Exporting Countries will consider curbing some of its production, according to Joseph Terranova, senior managing partner at Virtus Investment Partners. 

Investors who bought energy stocks last week, however, should use the recent pop to take some profits, Terranova said.

The trend for oil still seems to be lower, according to Josh Brown, CEO and co-founder of Ritholtz Wealth Management. While the energy stocks and oil are getting a nice bounce, the sector and commodity are coming from a "very, very deeply oversold" condition, he said. 

Pete Najarian, co-founder of optionmonster.com and trademonster.com, also said oil could be headed lower. However, he does like the airlines, which benefit from lower oil prices and are trading well on Monday despite the rally in oil prices. 

Stephen Weiss, founder and managing partner of Short Hills Capital Partners LLC, agreed, saying the airlines have long-term catalysts to push their stocks higher. Oil production remains high and that is unlikely to change anytime soon, he added. 

Elsewhere, Warren Buffett took a $4.5 billion stake in Phillips 66 (PSX) - Get Report , good for almost 11% of the company. So what does this say about the energy sector?

"This is not Warren Buffett saying this is the bottom in oil," Najarian explained. If anything, it says oil prices could stay lower for longer, as Phillips 66, a refiner, benefits from lower oil prices. 

This is a "fundamental signal that Warren understand the state of domestic oil," Terranova said. Terranova expects refinery stocks to do well in the current oil market. 

Buffett clearly feels like Phillips 66 can weather the storm, Weiss added. The company has a strong balance sheet and a solid dividend yield of almost 3%. 

Brown also likes Phillips 66, calling it his favorite among refiners. It helps that the stock has gotten cheaper in recent months. 

The conversation turned to Twitter (TWTR) - Get Report after SunTrust Robinson Humphrey's Bob Peck upgraded the stock to buy from hold and assigned a price target of $38.  The stock was up 3.3% on Monday afternoon.

Peck, a managing director at SunTrust, said Twitter is likely to hold a board meeting this week and announce a new CEO next week. He expects the CEO to be co-founder Jack Dorsey, and also expects President Adam Bain and Chairman Evan Williams to play larger roles at the company.

The CEO announcement will be a short-term -- albeit small -- catalyst, and Peck is looking longer term, too. The company's Lightning product rollout will come soon, as will its integration will Google (GOOGL) - Get Report. Those things could move the stock higher, especially if they help drive engagement and user growth. If those two measurements climb, so will monetization, Peck concluded.