Oil prices could weigh on market rally: Expert

The most important factor in market's direction: Pro
The most important factor in market's direction: Pro
This slow growth environment has potential: Pro
This slow growth environment has potential: Pro
Double-digit year for stocks?
Double-digit year for stocks?

A combination of headwinds will likely slow market momentum before early next year, and oil prices will prove crucial in the coming months, one expert said Tuesday.

After an October in which the jumped about 8 percent, the three major U.S. indexes climbed in November's first two trading days. The effect of slowing earnings and continued energy sector struggles could curb that strength, said Matt Maley, managing director at Miller Tabak & Co.

"We could have some upside here into the end of the year, but six months out, I think, it's harder to rally from here," he said on CNBC's "Power Lunch."

Traders work on the floor of the New York Stock Exchange.
Brendan McDermid | Reuters

Crude oil, which has fallen 20 percent this year, could determine where markets go, as it not only affects stock prices but also the high-yield debt market. Some energy companies have struggled to meet their obligations amid low commodity prices.

"Oil will have to rally a lot more for these companies to service their debt," Maley said.

Read MoreThese hot stocks could surge as economy sputters

Third-quarter corporate earnings are "not great" but have come in slightly better than expected, helping to float stocks higher, said Brad McMillan, chief investment officer at Commonwealth Financial Network. He told "Power Lunch" that the sentiment could drive stocks higher.

But investors need to "look through the headline" because companies have broadly lowered earnings expectations, said Jill Cuniff, president of Edge Asset Management.

"We're still in a slow-growth environment, but we can also move up modestly from here," she said on "Power Lunch."

Read MoreThis beaten stock is surging. More room to run: Traders