They allowed just 28 points in their final nine games, and even held their opponents scoreless in five of them. It's a feat that has not only earned the 1976 Pittsburgh Steelers and their "Steel Curtain" line the honor of being called the greatest defense ever, but one that is not likely to be matched anytime soon. It won't be replicated on the football field or on Wall Street, where Doug Cote, chief market strategist at ING U.S. Investment Management, says being too defensive is the riskiest trade of all.

"The defensive trade, (cash, gold, bonds) has been a disaster for investors," he says in the attached video, "while the riskiest trade (equities) has actually been the safe trade."

For those who think this risk-on trend is overdue for a reversal, Cote disagrees, and points to the fact that diversified portfolios split 60-40 between stocks and bonds are up about 3.3% through August, while the portfolio that's 100% invested in bonds is down about 4%.

"That's a 700 basis point spread and we think that continues" he says, noting that it is continuing so far in September.

To be clear, Cote's warning on being "overly defensive" does not apply to the sector level, where Staples (XLP), Health Care (XLV), Utilities (XLU) and Telecoms (IYZ) are typically characterized as such. In addition, his goal is to only get back to a 60-40 weighting, which is hardly sticking your neck out.

"That's still 40% bonds," he concedes, an allocation he calls a "risk-controlled strategy" that should outperform the overly defensive alternatives that have been lagging.

"Equities are cheap right now. They're a bargain. They're a great place to be and they'll beat bonds going forward."

This strategy is predicated on what Cote calls the "getting back to normal trade," which is essentially a call that the U.S. 10-year Treasury yield (^TNX) is going to get back to a ''normalized" level of 3.5% to 4% and corporate earnings can continue to deliver year-over-year gains.