The “Great Rotation” — the expected move that investors will, at some point, make from bonds to back to equities — has been used as a reason to be bullish on stocks. But Mark Hulbert says that reasoning may be flawed.

“I suppose it is conceivable. But a careful review of historical fund patterns doesn’t provide much support for this so-called Great Rotation argument,” Hulbert writes for MarketWatch. He says that at the end of 2012, the percentage of mutual fund assets allocated by investors to stocks was 65.7% — not a whole lot less than the 71% average since 1970. “Given that pattern, it is difficult to make the case that average fund investors are allocating an abnormally low share of their assets to stocks — or that they are about to increase that share,” Hulbert writes.

Hulbert also notes that a recent study found that, while stocks often rise when investors shift from bond funds to stock funds, “almost all of that increase is reversed within four months’ time.” And he cites another interesting recent study showing that “U.S. fund investors on average transfer assets from stock to bond funds during the winter months — and do just the reverse in summer.” That’s the opposite of the “Sell in May and go away” adage, and evidence that fund flows into stocks may actually be higher when the market is doing worse, Hulbert says. He also contends that much of the money moved out of bond funds won’t go into stocks, but into money market funds.