The price of West Texas Intermediate crude oil dropped to $81.07 per barrel last week. It now sits at just pennies above 4-year support. From around that level, sharp rallies followed back in 2010 and 2011.

During 2012 and 2013 the market for crude never reached that low at all. Crude oil bottomed in the $85-$92 range before rebounding.

You could make a generic play on a rebound in crude prices using any of the major oil-based ETFs listed above. USO, as an example, is very close to 4-year support. It has rallied sharply from that point, or above, five previous times since early 2011.

Another way to play could employ individual oil company stocks like Denbury Resources (DNR) or oil-field service firms like Schlumberger (SLB) and Helmerich & Payne (HP).

Denbury’s Oct. 24, 2014, closing price of $12.40 is well south of its absolute bottoms during 2010 and during all of 2012 – 2014. DNR's peak prices in every one of the most recent seven years provided exit areas north of $18.50.

DNR started paying quarterly dividends this year. Management preannounced their intent to double that amount in 2015. The current yield is 2.1% on today’s $0.625 quarterly distribution rate.

DNR shares are inexpensive at 11.9x already reduced 2014 and 2015 earnings projections, which reflects today's very depressed oil pricing. Any recovery in the price of crude could render those estimates way too conservative.

The market’s sharp sell-off during the week of Oct. 13-17, 2014, hit oil-related shares especially hard. SLB was knocked, very briefly, all the way down from June’s peak of $118.76 to about $85. That put the shares at valuation levels comparable to its previous four "best buying opportunities" as measured by both P/E and yield.

SLB bounced back to above $97 within days.

Helmerich & Payne showed similar, overexaggerated volatility. Its stock fell from a springtime pinnacle of $118.95 to near $75. It quickly shot back up to $90.42 by Oct. 21, 2014, before settling back to close at $86.98 last Friday.

HP pays a 69-cent quarterly dividend, giving shareholders a generous 3.17% current yield while they wait for oil prices to firm up again.

Stocks of oil companies have rarely been so shunned and despised. Brave independent investors were well rewarded for buying during past, similarly beaten-up periods.

Risk appears largely squeezed out of the oil group. Potential rewards look very appetizing. William Shakespeare may not have been an equity investor but his words are, nonetheless, very appropriate to investing in oil stocks today.

If you had the chance to lock in today's gasoline price for the next few years would you do it? If you answer that question, "Yes", then perhaps you should be buying oil and oil-related shares right now.