Investors holding the ultra-popular Nasdaq 100 and S&P 500 index funds have been hard hit over the last two weeks as tech shares have been roiled by rising U.S. Treasury yields.

Why it matters: Even though the economy is growing and many U.S. stocks are performing well, most investors are seeing their wealth decline because major indexes no longer reflect the overall economy or even a broad swath of public companies — they reflect the performance of a few of the country's biggest companies.

• That was all fine and good when Big Tech shares were booming higher, pushing their valuations to absurd levels, but the sea change in markets since the beginning of February has reversed that trend.

What we're hearing: “While the S&P 500 may be facing structural headwinds due to tech weakness, much of the rest of the market is actually doing quite well,” Tom Essaye, founder of Sevens Research, said in his daily Sevens Report.

• “Overall, most non-tech stocks are weathering the increase in bond yields quite well.”
• Essaye points out that while growth sectors like tech are barely positive for the year after a rough couple of weeks, value stocks and the S&P equal weight index (which gives all companies in the S&P 500 equal weighting rather than weighting them by their market capitalization) have delivered returns about double the S&P 500's.

By the numbers: Five companies — Microsoft, Apple, Amazon, Alphabet and Facebook — make up almost 25% of the market cap for the S&P 500, the U.S. benchmark index, and as more investors move toward passive investing, a greater share of their money is following these companies.

• As of December 2019, $4.6 trillion was indexed to the S&P 500, according to data from S&P Global, and $6.6 trillion was benchmarked to the index.
• Passive investing accounted for more than 60% of equity assets in December 2019 — with the majority linked to the S&P — and passive investing has grown since then.

The bottom line: Rising bond yields may not be bad for the economy or the stock market overall, but they have certainly been bad for the average Americans' stock holdings and retirement accounts.