Over the last 40 years, there has been a shift in the composition of assets in U.S. companies towards intangible assets, with latest estimates indicating that the level has reached $21 trillion—an amount that represents 84% of the value of the S&P 500. This according to an article in ETF Strategy.

So how can investors tap into this value? Since GAAP accounting principles focus on tangible assets, this “staggering tranche” of value doesn’t necessarily show up on a company’s books. According to the article, “One way is to understand that intangibles are made up of many subcategories, a large one of which is brand, and brand can be measured.” It explains that over the years academic research has been able to identify a link between powerful brands and strong financial performance. ”

The article, written by co-founder of the firm Brandometry, explains that her company is the first to create an “index leveraging brand measure to identify the right time to invest in undervalued strong brands. The EQM Brand Value Index was created utilizing brand data from CoreBrand analytics, a databased designed by academic Dr. Jim Gregory:”

CoreBrands, the article explains, tracks 500 large and mega-cap domestic brands on a scale of 1 to 100 based on three measures: strength of leadership, reputation, and investability. These qualitative measures are then combined with quantitative measures to “identify the largest disconnect between brand power and stock price.” The resulting index, Avarde writes, “is equal-weighted and comprises of 50 of the strongest brands for which various reasons are underpriced.”

The following chart shows a decade of EQM Brand Value Index contributors:

Avarde concludes by advising investors to “Value index because, as any good marketer knows, strong brands return to value, and now investors can enjoy the benefit.”