BALTIMORE (Stockpickr) -- U.S. stocks are off to a slow start in 2015. Since the calendar flipped to January almost a quarter ago, the big S&P 500 Index has only moved 1.76% higher. In short, investors need every edge they can get right now.

The good news is that you can get a pretty big edge on stocks by focusing on the stocks that are returning the most cash to investors.

How much of an edge? How about double?

You might think I'm talking about dividends here, but they're only part of the picture. Instead, the metric you should be looking for is "shareholder yield."

Shareholder yield is made up of anything that directly returns cash or equity to your portfolio. Yes, that includes obvious moves like dividends, but it also includes share buybacks and paying down debt.

Any of those three corporate actions can unlock significant value for shareholders, and the data backs it up. According to research by James O'Shaughnessy, over a 40-year period, large-cap stocks with the highest shareholder yield delivered average gains of 18.05%. That's almost double the average annual returns that investing in the big S&P 500 index would have earned you.

With low interest rates and record levels of cash sitting on corporate balance sheets, management teams are looking for the most effective ways to return value to shareholders. It's not one size fits all, either. The best mix varies from company to company. But by looking at the trifecta of dividends, buybacks, and debt extinguishment, you can be sure that you won't miss out on any of the proceeds.

With that in mind, here's a look at five names that have provided superior shareholder yield in the last year.

Juniper Networks

Up first is Juniper Networks (JNPR) - Get Report, the $9.6 billion IP networking equipment maker. Juniper owns the No. 2 spot in the market for high-end networking infrastructure, and the firm has parlayed that positioning into a decent start so far this year. In 2015, JNPR is up 5.2% so far. But management has paid out a whole lot more to shareholders in the last year. The firm topped our shareholder yield chart, with an 18.9% payout.

The biggest component of Juniper's shareholder yield was $2.26 billion in buybacks over the last year.

Being the No. 2 network infrastructure stock comes with a few notable advantages. While bigger rival Cisco Systems (CSCO) - Get Report earned about 10 times Juniper's revenues last year, Juniper is able to move the needle on its income statement through relatively small gains in market share. Likewise, there's a big tailwind pushing at the backs of network equipment stocks right now, as increased bandwidth demands force infrastructure upgrades, and drive sales for the whole industry. As Juniper continues to capture a meaningful chunk of switch and router sales, the firm has a downhill battle for growth.

Juniper has been in the process of cutting its cost structure, a move that it hopes will boost margins over the long-term. Shorter-term, JNPR's profitability has been hit by some one-time charges, but overall the firm remains in fine financial shape. Juniper currently carries $1.84 billion in net cash and investments, enough to pay for 19% of the firm's current market capitalization. That's a big risk reducer for investors today.

LyondellBasell Industries

LyondellBasell Industries (LYB) - Get Report is another stock that's having a pretty good start to 2015. Since January, this $41 billion Dutch chemical maker has pushed 8.5% higher, stomping the S&P's barely-breakeven performance. And that's not counting LYB's hefty shareholder yield payout. Between dividends and buybacks, LYB paid out 15% of its market cap back to investors last year.

LyondellBasell is one of the largest producers of plastics and commodity chemicals in the world, with a footprint that spans 18 countries. The firm also has a large energy refining presence, contributing approximately a tenth of its overall revenues. LYB's plastics are used in nearly every manufacturing process out there, from furniture to interior panels on cars. That means that, as personal consumption spending keeps climbing, so too does sales volume in the biggest part of LYB's business. Despite big exposure to commodity chemicals, LYB's net margins consistently scrape up against the double-digit mark.

And even though chemical manufacturing is capital-intense, LYB has more than half of its $7.1 billion debt load covered by cash and investments. That gives LYB plenty of wherewithal to keep returning value to shareholders in 2015. This stock's momentum is pointed higher. It should keep on outperforming in the near-term.

Mosaic

$17 billion fertilizer stock Mosaic (MOS) - Get Report is another commodity-linked stock that's been shoveling cash back to its shareholders in record amounts. In the last year, Mosaic returned $2.37 billion to investors in the form of dividends and buybacks, adding up to a 13.8% shareholder yield.

Mosaic is inseparably tied to agricultural commodity prices. As one of the world's largest producers of phosphate and potash fertilizers, Mosaic's customers are the commercial farming operations that live and die by soft commodity prices. The firm is vertically integrated, involved in everything from mining to production to wholesale distribution. Size is a big advantage in the asset-intense fertilizer business, and MOS' huge scale means that it's able to have a meaningful impact on industry-wide supply (and thus prices).

Mosaic has been facing big headwinds thanks to the continued rise of the dollar, and it's resulting downward pressure on agricultural commodity prices. But as the Fed hints at the possibility of interest rates, central bankers are likely to start taking a more active role in ensuring that the dollar isn't allowed to keep rallying unchecked.

Despite all of the headwinds of recent years, MOS still earns net margins well above 10%, and while not dirt cheap, shares are trading for a discount vs. the rest of the market right now. Investors should be paying attention to the big cash payouts this company has been handing out to its shareholders in the past year.

SanDisk

Flash memory maker SanDisk (SNDK) has had a less auspicious start to the year. Since January, SanDisk has dipped by about 13.5%, shoved lower by an earnings call in late January that fell short of investors' expectations. But while the market hasn't exactly been kind to SNDK in recent months, the company's management has. The firm paid out more than $2.3 billion in buybacks, dividends and debt extinguishments in the last year. That all adds up to a whopping 12.96% yield at current levels.

SanDisk is the biggest name in the NAND flash memory business, and that's saying a lot. Flash memory continues to make its way into more and more devices, as consumers seek smaller form factors and applications demand faster speed than conventional hard disk drives can offer. That's particularly true in the mobile device market, where the use of flash storage is universal, and replacement cycles are extremely short. As demand for flash climbs, so have the number of firms supplying it, which is why SNDK's big patent portfolio is such a big deal in the next several years. It means that the firm benefits from the overall growth of the NAND flash memory market, regardless of who's manufacturing the memory.

Today, SanDisk trades for just shy of $85 per share, but what many investors don't realize is that a whopping $16 of that share price is paid for by net cash and investments on SanDisk's balance sheet. That big cash cushion, coupled with SanDisk's correction at the start of the year, makes this shareholder yield standout look relatively cheap vs. its high-growth computer storage peers.

General Dynamics

Last on our list of shareholder yield winners is defense contractor General Dynamics (GD) - Get Report. GD earns 70 cents of every sales dollar from the U.S. government. The firm sells Uncle Sam everything from submarines and jets to computer systems. Increasingly, GD has found growth in its commercial aviation unit, which builds Gulfstream business jets.

GD's deep expertise building complex machines and systems gives it a deep economic moat. A new competitor can't just step in and develop a new submarine or tank program to sell to the government -- at least not without incurring prohibitive costs. Similarly, the firm owns huge infrastructure assets, like three of the six major submarine shipyards in the U.S.

GD owns similar moats in its commercial aircraft business, which owns a third of the global market for medium and large business jets. Even though the bizjet business is extremely cyclical, a combination of growing corporate profits and low oil prices should help spur continued growth in the space. In recent years, Gulfstream's core business has been once of the few pockets of the ex-airline aviation market that's actually experienced growth.

Last year, GD paid out $4.7 billion in dividends, buybacks, and debt extinguishment, totaling a 10.5% shareholder yield.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.