Like pro athletes, investors are always looking for that extra edge to juice their returns. Some turn to momentum trading or complex hedging schemes, while others put themselves in precarious margin positions.

In an effort to pick stocks on the upswing, investors often look at buybacks and insider buying as positive signals. The logic is noble -- put faith in those who have faith in themselves. But there's mounting evidence that these signals don't set investors up for any particular success.

The lure of the big buyback
Why have corporations been big on buybacks lately? For one thing, a few years of solid economic growth have left them flush with cash, even as they've watched their stock prices drop over the past year. Recent multibillion-dollar buybacks include IBM's (NYSE: IBM) $15 billion authorization, announced in February, and the three-year, $30 billion repurchase plan Procter & Gamble (NYSE: PG) announced last August.

These announcements seem as though they'd point to strong businesses with cheap shares, but a recent study from Standard & Poor's does not back that up. It said, "While some S&P 500 companies have used buybacks judiciously, repurchasing at discounts to recent share prices, most companies have been too enthusiastic with their stock-buyback programs and have not increased shareholder value."

So repurchase plans don't signal that outperformance is on the way. The same goes for insider purchases, according to a recent paper from two German finance professors, who argued that "insider trades do not reveal exploitable information." As evidence, consider that numerous insiders at Thornburg Mortgage (NYSE: TMA) were buying significant amounts of stock in late 2007 -- at prices more than three to eight times the shares' current value.

A better way
The key to earning superior returns is not timing the market, but rather spending time in the market -- particularly if you hold great, dividend-paying companies over the long haul.

For example, let's say that an investor bought $10,000 worth of stable, dividend-paying stock, then held it for 25 years. We'll assume 8% annual appreciation in shares, plus a constant 3.25% dividend yield paid at the end of each year. If you took those dividends each year and spent them, your 8% appreciation would still leave you with $68,485 after 25 years. Very nice.

But reinvesting that annual dividend could more than double those returns. With dividends reinvested in the example above, your total after a quarter-century would exceed $140,000.

The Foolish takeaway
Eager to turn this example into reality? There are plenty of fundamentally strong public companies paying a dividend large enough to double your returns over time. Consider a few that offer direct investment plans:

Company

Annualized
25-year return*

Current Yield

Pfizer (NYSE: PFE)

13.9%

6.2%

Bristol-Myers Squibb (NYSE: BMY)

10.4%

6.1%

Dow Chemical (NYSE: DOW)

11.6%

4.6%

*With dividends reinvested. Current yield subject to change.

James Early and Andy Cross, our analysts at Motley Fool Income Investor, regularly put hundreds of high-yielding companies under their microscope, recommending two each month. Pfizer and Dow Chemical have already made their list of picks.

To learn more about all the selections, and how to double your returns through dividends, check out a no-obligation 30-day free trial.