Just a few weeks ago, the Pouting Pundits of Pessimism were freaked out over the potential for the yield curve to invert. They've now completely reversed course and are freaked out over a 3% 10-year Treasury note yield.

All this gnashing of teeth is driven by a belief that low interest rates and QE have "distorted" markets, created a "mirage," a "sugar high" – a "bubble."

These fears are overblown. Faster growth and inflation are pushing long-term yields up – a good sign. And, yes, the Fed is normalizing its extraordinarily easy monetary policy, but that policy never distorted markets as much as many people suspect. Quantitative Easing created excess reserves in the banking system but never caused a true acceleration in the money supply. That's why hyper-inflation never happened and both real GDP and inflation remained subdued. Profits, not QE, lifted stocks.

And our models show that low interest rates were never priced into equity values, either. We measure the fair value of equities by using a capitalized profits model. Simply put, we divide economy-wide corporate profits by the 10-year Treasury yield and compare these "capitalized profits" to stock prices over time. In other words, we compare profits, interest rates, and equity values and determine fair value given historical relationships. The lower the 10-year yield, the higher the model pushes the fair value of stocks.

Because the Fed held short-term rates so low, and gave forward guidance that they would stay low, they pulled long-term rates down, too. As a result, over the past nine years, artificially low 10-year yields have caused our model to show that stocks were, on average, 55% undervalued.