After a summer sell-off, stocks are set to end October with their biggest monthly gain since 1974. At the same time, interest rates rose every week during the month, capping the longest losing streak for bonds in two years. The yield on the 30-year bond has risen to 3.2% from 2.7% and the 10-year-note has jumped to 2.2% from 1.7%.

Though the moves look small when compared to the wild swings in stocks, a greater shift in trend for bonds could be underway.

Despite the Federal Reserve's "Operation Twist" intervention to lower intermediate-term rates, three Treasury bond ETFs of different durations are trading below their 50-day moving averages: the iShares Barclays 1-3 Year Treasury Bond (SHY), iShares Barclays 7-10 Year Treasury (IEF) and iShares Barclays 20+ Year Treasury Bond (TLT) . Recall that bond prices move inversely to interest rates.

The weakness in bonds has been pegged to a variety of factors, from inflation to Europe. But when making asset allocation decisions, investors should pay more attention to why a market moves than how it moves.

Bull and bears markets can walk across several news cycles. Take gold. The yellow metal's decade-long bull run has been explained away by everything from the Iraq War to weakness in the dollar. Explanations pass. The trend persists.

The 6-month correlation between stocks and bonds (using the SPDR Dow Jones Industrial Average ETF (DIA) and iShares Barclays 7-10 Year Treasury as proxies) now rests at -0.92. This means that, on any given day a rise in stocks is nearly always accompanied by a drop in bond prices (and rise in interest rates), and vice-versa.

And, despite the meaningful move higher in rates, investors still prefer going long stocks. A short bond trade, however, may pay even greater rewards. Unlevered funds which rise with interest rates like ProShares Short 20+ Year Treasury (TBF), iPath US Treasury Long Bond Bear ETN (DLBS) , iPath US Treasury 10-year Bear ETN (DTYS) and iPath US Treasury 2-year Bear ETN (DTUS) have shown only relatively modest interest from the herd.

The herd is often late. Nasdaq climbed from 1000 to 5000 before most investors finally got on board. Gold was up for years before becoming a popular trade.

Big moves are volatile and take time. But for now, I'm short short the bond market and willing to go for a ride.