This chunk of the US population is set to inherit a staggering $9 trillion in next decades, report says. Here's who will be giving — and receiving — in the next 'great wealth transfer'

In this instance, the movement of money to spouses or partners has been dubbed the "horizontal wealth transfer” since the wealth isn't changing generations — yet. An estimated $9 trillion is expected to be transferred “intra-generationally,” from one spouse to another.

This means that, by 2030, this horizontal wealth transfer will likely have reshaped wealth management in the country — a landscape that has largely been dominated by men.

Here's why this is happening — and what it means for the economy.

Women stand to inherit a fortune

A 2024 Global Wealth Report from UBS revealed that an estimated $9 trillion is going to transfer intra-generationally in the coming years, with the funds moving from one spouse or partner to another.

Women are most likely to be the recipients of this money, as they tend to outlive their male spouses.

In fact, according to the consulting firm McKinsey & Company, in the case of heterosexual couples, wives tend to live an average of five years longer than their husbands. As a result, they'll end up with the cash.

However, McKinsey's data suggests women may accumulate even more wealth than the UBS report projects.

According to McKinsey's research, around one-third of financial assets across all households are currently under the control of women. That's more than $10 trillion.

By 2030, however, their research shows women are estimated to control around three times that amount, or the majority of the $30 trillion baby boomers will collectively own at that time.

McKinsey's report suggests this massive transfer of wealth to (mostly) women will be of "such magnitude that it approaches the annual GDP of the United States."

What does this wealth transfer mean?

For many wealthy boomer couples, men are the primary decision-makers regarding money matters. McKinsey's research shows that men make key financial decisions in two-thirds of all affluent households in the United States.

When women take control of wealth after their partners' deaths, it will affect the global financial economy. Data shows women are more likely to seek professional financial advice, are less risk tolerant when it comes to investing, and are more likely to give money to groups supporting women.

If you're one of those women who stands to inherit down the road, you probably aren't too concerned about the worldwide impact of the horizontal wealth transfer, but you may still be overwhelmed at the prospect of managing a significant windfall.

The good news is that, often, the best thing to do is… nothing. If the money is already invested in low-cost index funds and you have the right portfolio asset allocation already in place, you can just continue to withdraw from the accounts at the same rate.

If you already have an updated will in place and don't want to change your beneficiaries, you can also maintain the status quo. Estate taxes also generally don’t apply when money is transferred from one spouse to another.