In recent weeks, the world’s most highly valued technology company, Apple, increased its annual dividend per share by more than 10%. Exxon, America’s largest energy company, raised its annual payout by nearly 6% per share. In an environment where profit growth on the S&P 500 may be plateauing, the fact that America’s two largest dividend-paying companies announced healthy dividend increases is, I believe, a healthy signal for the overall U.S. stock market.

Of the top 20 dividend-paying companies in America, listed below, six typically raise their annual dividend payments during the quarter that will end on June 30. The good news is that five of those six already have done so. In addition to Apple and Exxon, Johnson & Johnson, Wells Fargo and Proctor & Gamble have all announced dividend increases in recent weeks. Only Chevron, contending with lower oil prices, has chosen to maintain its dividend at current levels.

Top Twenty Largest Indicated Dividend Payers

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Dividend growth matters because, over time, it propels equity markets to higher levels. Today, roughly 88% of the weight in the S&P 500 Index is in dividend-paying stocks.1 Dividend-payers are not minor players in the market; these stocks are driving nearly 90% of the return of the U.S. stock market.

How, then, are dividend payers progressing this year as a category with respect to their aggregate dividend growth? On November 30 of each year, WisdomTree identifies all the common stocks and real estate investment trusts (REITs) that pay regular cash dividends. Those that pass our market capitalization, liquidity and other selection requirements typically are included in the WisdomTree Dividend Index, the broadest measure of U.S. dividend-paying stocks. Last year, the more than 1,400 companies selected for inclusion in the WisdomTree Dividend Index were indicated to pay more than $410 billion in cash dividends for the coming year, based on their most recently declared dividend per share.2 As the table above demonstrates, of the 20 largest dividend payers in the U.S., 13 have already raised their dividend per share since the end of November. Overall, we estimate that the aggregate Dividend Stream® for all the companies in the WisdomTree Dividend Index increased 4% between November 30, 2014 and April 30, 2015. This suggests to me that aggregate dividend-per-share growth in the U.S. could once again approach double digits in 2015.

This is a bullish sign for the market for two reasons. First, over the past 60 years, while the total return of the S&P has averaged about 10.5% on an annualized basis, aggregate dividend growth has compounded at roughly 5.5% per year.3 So 2015 is shaping up to be a year in which overall dividend growth will likely outpace its long-term average. Second, in a world of low and negative interest rates, higher aggregate dividends increase the floor upon which the U.S stock market can be valued. This will become particularly important should first-quarter share profits on the S&P 500 decline relative to the first quarter of 2014. If corporate executives are confident enough to keep increasing dividends during a period when earnings slow or contract, it may be a signal that they believe the current earnings lull is temporary.