Is the Tooth Fairy feeling Wall Street's pain?

The business of being a kid took a turn for the worse last year, at least according to one gauge.

Perhaps expecting a hit to her 401(k) plan, the Tooth Fairy took a thriftier stance in 2015, with children who left their pearly whites under a pillow in hopes of receiving cash finding that their morning take was 10 percent less than the previous year.

A tooth fetched an average of $3.91 in 2015, down from $4.36 the year before, according to Delta Dental Plans Association, a nonprofit association of benefits providers. The first lost tooth, which typically nets the greatest haul, also took a hit in the value department, falling just over 9 percent.

According to the group, parental giving for their kids' teeth has tracked the movement of the S&P 500 in 11 of the past 12 years. In 2015, by contrast, "the Tooth Fairy must have been using predictive analytics, as the market continues to take losses beyond the 8.2 percent drop during the time the survey was conducted compared to 2014," Delta Dental said in a news release.

On the other hand, the Tooth Fairy may have been feeling less generous after the publication of a column by a Financial Times' personal finance editor calling for her demise for the crime of encouraging children to believe myths about money.

The Tooth Fairy seemingly varied her rates by region, paying an average of $5.27 for a tooth in the Northeast, $4.25 in the West, $3.36 in the South and $3.11 in the Midwest.