It was the first time since October that oil prices fell below $70 per barrel.
Crude and natural gas prices move for very different reasons, but when there is a sell-off in oil markets, a lot of that money can flow into natural gas contracts.
Trading volumes in natural gas this week have nearly doubled.
A lot of money is flowing out of crude contracts because the dollar has finally showing some life after months in the doldrums.
Crude is bought in U.S. currency and for most of this year the dollar has been falling, meaning that investors holding stronger currencies can get more crude for less money.
Since the beginning of the year, the price of a barrel has nearly doubled.
Crude was trading above $78 per barrel on Dec. 1 when the dollar bounced off 15-month lows. In that same span of time, crude has fallen by more than $8 per barrel, while the prices of natural gas has jumped nearly 12 percent.
Also helping boost the price of natural gas are winter storms that are spreading from the Midwest to the East.
Temperatures dropped to 10 degrees from Des Moines to Chicago, and frigid winds have forced chill values as low as negative 25 in parts of Wisconsin, Iowa and Illinois, according to the National Weather Service.
"The weather is a significant driver here," analyst and trader Stephen Schork said. "It's about as bullish as it can get this year."
That's unlikely to mean higher heating costs where natural gas is used.
Utilities have long since locked in cheap prices and that is passed on to homeowners. A number of utilities have already sent out notifications that rates are coming down.
Heating oil is another story because it generally follows the price of crude. The price for heating oil has jumped nearly 40 percent since February, though like crude, those prices have begun to fall.
Perhaps keeping natural gas prices in check are unprecedented volumes being held in storage.
It has been a mild winter so far and the worst economic downturn in generations has destroyed demand from big energy users like manufacturers.
Storage of natural gas is above listed capacity in the West, and at or near capacity everywhere else.
The Energy Information Administration reported that levels dropped by 64 billion cubic feet last week, the first reported draw since the week of March 13.
Natural gas for January delivery jumped 42.3 cents to $5.32 per 1,000 cubic feet on the New York Mercantile Exchange. Prices rose as high as $5.335 earlier in the day.
Benchmark crude for January delivery gave up 42 cents to $70.25 a barrel on the Nymex. Prices dropped as low as $69.81 a barrel earlier in the day.
At the pump, retail gas prices dropped slightly overnight to a national average of $2.629 a gallon, according to auto club AAA, Wright Express and Oil Price Information Service. A gallon of regular unleaded is 2.9 cents cheaper than last month but 94.6 cents more expensive than the same time last year.
In other Nymex trading in January contracts, heating oil lost 1.67 cents to $1.8926 while gasoline lost 2.83 cents to $1.829 a gallon.
In London, Brent crude for January delivery fell 92 cents to $71.47 on the ICE Futures exchange.