The S&P 500 index continues to hover near its record high—standing 4 percent beneath it Tuesday—but that doesn't mean all is well with stocks, says star mutual fund manager John Hussman, president of Hussman Investment Trust.

"We remain focused on the lessons of a century of history," he writes in his weekly commentary. "The most historically reliable valuation measures continue to project zero total returns for the S&P 500 over the coming decade."

The key issue here is "the behavior of market internals, credit spreads, and other risk-sensitive measures," Hussman maintains.

"In short, it’s the deterioration in market internals and other risk-sensitive factors, and emphatically not simply elevated valuations alone, that suggests a much different and far more vulnerable environment here than we’ve observed for the majority of the period since the 2009 low."

Among the negative internals is decreasing breadth, which means that as the market moves higher, fewer and fewer stocks are participating in the rally. And credit spreads remain at historic lows.

Elsewhere on the investing front, Peter Hodson, CEO of 5i Research, an investment research firm, has put together a list of five important points investors should know, but may not.

The list includes:

• "Diversification does not need to be overly complicated," he writes in the Financial Post of Canada. "Most mutual funds hold hundreds of securities, which is why most funds can’t beat the market. Academic studies have proven that the additional value of diversification diminishes beyond 15 different securities." So keep your numbers down.
• "Dividend growth stocks beat everything else," Hodson says. Studies conducted by University of Pennsylvania finance professor Jeremy Siegel show that more than 90 percent of the stock market's long-term historical returns come from reinvested dividends. "Many investors make the mistake of seeking out high-yielding dividend stocks," Hodson explains. "But they may be surprised to know that, historically, a company paying a 1-percent dividend that can grow its dividend is far superior to a company paying a 7-percent dividend that can’t grow."

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