A new study offers some telling statistics about high-net-worth women, including this one: 69 percent of women with US$5 million in investable assets are the primary financial planning decision makers in their households.

RBC Wealth Management sponsored the study, done by The Economist Intelligence Unit, of high-net-worth women and men. Respondents included a total of 502 women and 549 men in Canada, the U.S., the U.K., mainland China, Hong Kong and Singapore, and all had US$1 million in investable assets or more. The Western countries were 79 percent of the sample and Asia the remainder.

RBC acknowledges there are still far more high-net-worth men than women. But among the wealthiest individuals -- those with US$5 million or more in assets -- women and men respondents were represented in roughly the same proportions: 27 percent men and 22 percent women. The fact that nearly 70 percent of the wealthiest women say they are the ones making financial planning decisions in their households ought to be a wake-up call for planners and the profession. Assumptions shouldn’t be made that wealthy female clients, even those who are part of a couple, are not driving financial planning decisions.

“Our survey underscores the increasingly prominent role women are assuming in the high-net-worth universe and suggests their influence is likely to continue to rise given the number of younger women who see significant opportunities to generate wealth,” says RBC.

In particular, the survey found millennial women (which the survey defined as those born between 1981 and 2000) are entering the highest levels of asset ownership faster than baby boomers (born 1946-1964). The survey found 32 percent of HNW millennial women have $5 million or more in assets compared with 22 percent of baby boomer HNW women. That stat correlates with the finding that younger women more often than older ones have gained their wealth through running a business rather than through an inheritance. About half of millennial women became wealthy from a business compared with 37 percent of baby boomer women, the study said.

A closer look at the statistics on financial planning show significant numbers of HNW women are primary decision makers, and the percentage increases dramatically with younger women: 72 percent of millennial women said they were the primary decision maker for financial planning vs. less than half of boomer women. Wealth did make a difference though: As mentioned earlier, 69 percent of the wealthiest women say they are primary financial planning decisions makers in their households vs. just over half of HNW women overall.

The survey offered many more interesting findings on how HNW women and men, and younger vs. older women, compare on impact investing, charitable giving and tackling social issues. Click here to read more.