Income investors have two equally important objectives when it comes to investing -- obtaining high amounts of income and limiting risk.

Many survivors of the 2008 bear market learned this the hard way. They found out that they must either balance the two, or face heavy losses.

Case in point: Many investors jumped at abnormally high yields in financial stocks such as Citigroup (NYSE: C) when its yield jumped above 10% shortly before the company eliminated its dividend. And investors looking for a bargain in General Electric (NYSE: GE) endured a dividend cut of almost 70%.

Remember, these are companies that were once widely assumed to be among the safest in the world, yet they eliminated their dividend practically overnight.

To be fair, these were also extraordinary circumstances that happened during a financial crisis. But long-time income investors still follow a general rule of thumb -- 'The higher the yield, the riskier the stock.'

Today, I'm making an exception to this rule. As I mentioned to you a few weeks ago, there is a way to invest in stocks with great yields, but without all the added risk that comes from dividend cuts.

Let me explain.

As you've probably heard in the past, high yields are often a sign that a company is in trouble. And determining whether a high dividend payout is sustainable can be challenging and usually requires a detailed analysis of the company's financial statements.

Wall Street firms employ analysts to do this task but their research isn't widely available. Usually only large customers -- institutional investors, hedge funds, and high net worth individuals -- have access to this research, which gives those investors a chance to sell ahead of dividend cuts.

But while you, the individual investor, can't always get Wall Street firms to share their research, you can follow what the largest investors are doing by observing the price action of individual stocks.

When hedge funds and other large investors are buying, we should see the stock outperform the market. This can be measured with an indicator known as relative strength (RS).

Relative strength quantifies how any individual stock is performing compared to all of the other stocks in the market. The actions of large investors can be seen in RS. When they are buying, the stock price should be rising, and when they are selling, we will usually see the stock price lag the broader market. RS summarizes this buying and selling pressure in a single indicator.

Using RS to buy market leaders and avoid laggards is one of the best ways I know of to beat the market.

It's such a powerful indicator, it could have told you exactly when to buy and sell Apple (Nasdaq: AAPL), for example. The RS indicator would have recommended buying Apple at a price of $460 per share in February 2012, when its RS was showing above 70 (I recommend stocks with an RS over 70, which means they are outperforming 70% of the market). After the purchase, we would then hold onto our shares until RS fell below 70 -- the point when Apple had become a laggard among larger investors -- when Apple's share price reached $650.

If we sold at the $650 share price, we would have pocketed a tidy 41% return in just eight months. That would be well before the stock plummeted 31% to where it is today, languishing back around $450 per share.

In other words, the RS indicator shows investors an ideal time to buy a stock, pocket gains -- plus any dividend income -- and sell long before they lose their shirts.

Unfortunately, there is never a free lunch on Wall Street -- using RS alone is only half of the work.

While high RS stocks can provide higher-than-average gains, some come with a great deal of risk. For example, these could be the kind of stocks that suffer large declines when the company misses earnings estimates by a penny.

To help minimize this risk, I look for high RS stocks with strong fundamentals. When it comes to income stocks, I look for companies that have increased their dividend payments during the past three years, have sustainable yields and sport growing cash flow.

Companies with strong fundamentals in these areas tend to be the biggest winners in the long run. Those looking closely would have seen that fundamentals in both Citigroup and GE were deteriorating in 2008 as their rising dividend yields made the stocks look otherwise attractive to many investors.

Both relative strength and fundamental analysis have merit in finding market-beating stocks, but what happens when we put these two methods together?

After a great deal of research and testing, I created a trading system that combines both relative strength and fundamental analysis. I call it the 'Maximum Profit' system. Its rules help us identify stocks that are likely to outperform the market during the next six months to a year with lower-than-average risk.

The results from using this method have been outstanding -- over a decade-long test, the Maximum Profit system generated a massive 571% total return. Its rules can be applied to any list of stocks, and in every test I have run, the system beats the market. This is true whether I test large caps or small caps, growth or value stocks, or any other group.

And best of all, if the system recommends a dividend-paying stock, the system's safeguards make it virtually 'bulletproof.'

Here's an example of an ideal 'buy' for income investors using the Maximum Profit system -- oil and gas partnership Delek Logistics Partners (NYSE: DKL). The company has a high RS of 77, which means it is outperforming 77% of the market and is in favor with larger investors. And even though the company has only been publicly traded since 2012, its earnings have grown 44% a year since 2002. Besides just being undervalued, it also pays a dividend yield of 4.8%.

Thanks to the system -- which puts this stock's relative strength and strong fundamentals to the test constantly even after I buy it -- I can hold onto a solid dividend stock like this one without much worry. Even if things happen to go south for this company, the system will tell me long before the stock takes a plunge or cuts its dividend -- which could prevent me from losing thousands of dollars.