NEW YORK (MarketWatch)—U.S. stocks could use a bit of holiday cheer. As November draws to a close, ushering in the final weeks of the year, the market is battling an insidious villain: cheap oil.

Forget that the Dow Jones Industrial Average registered its 31st-record close in a thinly-traded, holiday-abbreviated session Friday.

The S&P 500 SPX, -2.26% is up 11.86% year-to-date, 3.5% for the month, the Nasdaq COMP, -1.41% has advanced 14.7% this year, gaining 3.5% on the month, while the Dow DJIA, -2.85% added 7.5% so far this year, 2.5% in November.

Those gains may be under pressure in the wake of the Organization of Petroleum Countries deciding not to cut its 30-million-barrel-a-day oil production target, in an effort to maintain leverage over world oil prices.

That decision, made on Thursday, by the 12-member cartel has sent oil futures on a severe two-day tumble. Light, sweet crude oil CLF25, for January delivery recorded an 18% drop in November, its steepest monthly decline since 2008. Brent crude UK:LCOF5 also endured a similar monthly plunge, not to mention the significant daily decline.

Although oil’s retreat is great for consumers, it could spell trouble for the U.S. economy at large, or at the very least, translate into bad news for shale oil producers, which have fostered U.S. employment growth.

As MarketWatch columnist Philp Van Doorn puts it: For those pummeled U.S. companies focused on shale-oil fracking, which is more expensive than pumping oil out of wells, “long-term expansion plans may have to be severely curtailed.”

Stocks in December will have to power through concerns about the long-term implications of oil-price declines. Deflationary pressures already are being felt in the eurozone due to slackening energy prices—which could force the European Central Bank to enact a full-blown stimulus plan to reinvigorate the sluggish region.

Santa Rally? Let’s hope!

U.S. investors have to hope that December follows its usual trend and comes bearing gifts, not a lump of coal. Here are a few stats about the Dow’s performance in December worth considering:

The Dow has ended positive in five straight Decembers starting in 2009

December boasts the best average gain for the year 1.43% (July is second with 1.34%)

1903 marked the best-ever performing December with a 10.78% gain

December has produced a gain in 84 of 117 years, or roughly 72% of the time (excluding 1914)

The worst performing December was 1931 with a loss of roughly 17%

Earnings

The earnings calendar for Monday includes only Mattress Firm Holding Corp. US:MFRM expected, after the closing bell.