Last October, as U.S. oil prices seemed to be stabilizing around $45 a barrel (bbl), some bullish traders chuckled at the notion of U.S. shale firms racing to hedge production at what they thought was the bottom of a 19-month rout.

Now, a handful of producers such as Anadarko Petroleum Corp. (NYSE: APC), which sporadically hedges in large chunks every few quarters, and natural gas giant Chesapeake Energy Corp. (NYSE: CHK) could have the last laugh.

They were among the few to increase hedging in the fourth quarter, according to a Reuters analysis of filings from the largest shale firms. That group locked in prices for nearly 38 MMbbl of future production just before crude tumbled another $15/bbl in the early weeks of 2016.

However, the figures show that taken together, the 28 analyzed companies ended the quarter with about 28 MMbbl fewer hedged for a total of 291 MMbbl that were hedged, than when they started. Analysts estimate that between 15% and 20% of 2016 U.S. oil production is hedged while as little as 2% is for 2017.

Additionally at the end of 2015, about 44% of the group's outstanding hedge book was concentrated in the hands of just eight U.S. shale oil companies that increased their outstanding oil options, swaps or other hedging positions.

In the third quarter, amid an almost uninterrupted decline in prices, only six companies had boosted their hedge positions.

The data underscore a growing chasm between those that remain hedged and producers that are not, raising doubts how long the latter can survive the lower-for-longer price scenario.

"The path higher for prices will be fairly slow and steady because once we get back to the $45-$50 range, you'll hit a wall of financial hedges that will cap prices," said Michael Tran, director of commodity strategy at RBC Capital Markets, who expects the market to rebalance in the second half of the year.

In all, 16 companies ended the quarter with hedging positions reduced by a total 66 MMbbl, mostly as a result of expiring hedges - a long-anticipated trend that leaves most of the industry with little insurance to ride out a market expected to trade below $40/bbl through the year.

Foremost among those opting out of further hedges was Devon Energy Corp. (NYSE: DVN), which let insurance on about 14 MMbbl expire in the fourth quarter. Last month, Devon said that it would slash its dividend and capex by 75% and lay off one-fifth of its staff.

Analysts who track shale producers say sufficient cash flow that hedging can provide is key to a company's health and ability to sustain production, yet most producers chose not to hedge.

For cash-strapped drillers, hedging could have simply become too expensive, analysts say. Some producers also seem perpetually bullish and have passed up opportunities to hedge even at $20 or $30 above spot prices in recent quarters, betting prices will soon recover.

Now, analysts say those producers might need to rethink their strategies.

"We're seeing sharp cuts from some producers this year in both cash and budgets," said John Saucer, an analyst at Mobius Risk Group in Houston. "At the end of the day, the lack of hedging has come back to get them."

Lacking 'Motivation'

Despite oil prices bouncing to nearly $40/bbl this past week, some traders say ballooning inventories suggest further declines ahead.

In a note on March 11, Goldman Sachs cut its 2016 price forecast by $7 to $38/bbl, adding that the recent rally would prove "self-defeating" as sustained low prices are necessary to finish supply-demand rebalancing.

Those who boosted hedging include QEP Resources Inc. (NYSE: QEP), which added 3.3 MMbbl for a total of 6.6 MMbbl for 2016 at $58/bbl, along with 2.6 MMbbl for 2017 at $54/bbl. Carrizo Oil & Gas Inc. (NASDAQ: CRZO) added nearly 2.3 MMbbl at an average price of $60/bbl.

Chesapeake Energy also added 4.4 MMbbl.

The problem is that decade-low prices mean some producers simply cannot afford to hedge because the prices remain below marginal costs.

In a recent conference call, Anadarko's CEO told analysts he did not think "any company has got a motivation to hedge" at $30 oil.

Anadarko hedged an additional 20 MMbbl last quarter, which accounts for about 11% of its 2016 book.

In November, Continental Resources Inc. (NYSE: CLR)-- which sold off all its hedges in 2014 -- said last month it expected to cut output this year by 10%.

Last month, Whiting Petroleum Corp. (NYSE: WLL) -- which let nearly 6 MMbbl expire last quarter - said it would suspend all fracking and spend 80% less in 2016. The North Dakota oil producer has 20 MMbbl hedged for 2016, which accounts for about 8% of output.

To be sure, not all producers hedge voluntarily. Dealers indicated a large number of hedges in recent weeks and months have been prompted by banks that require borrowers to hedge a certain part of production for upcoming quarters.