There are a number of ways individuals can use their pocketbooks for good, including donating to help the victims’ families pay for their funerals and other expenses.

Another option is to divest your money from weapons manufacturers and companies that materially benefit from gun sales. This is a practice that has picked up steam in recent years as a way for investors and consumers to ensure their dollars aren’t funding things they’re morally opposed to.

“It’s amazing how much power people have in their money, in their savings, in their 401(k) plans,” says Andrew Behar, CEO of As You Sow, a nonprofit that promotes corporate social responsibility through shareholder advocacy. “It really just comes down to: Do you want to profit off of assault weapons, handguns, and ammunition? If you don’t, you need to know what you own.”

How to divest

There are two publicly traded gun manufacturers: Sturm Ruger (RGR) and Smith & Wesson Brands (SWBI). Both of these companies are too small to be included in something like the S&P 500, but they may be present in a small-cap index fund, an extended market fund, or a total market index fund, according to Morningstar.

If your biggest concern is gun manufacturers, then something like a S&P 500 index fund is a “safe” investment. But it gets more complicated when you consider retailers that sell guns or ammunition, Morningstar notes. An investor morally opposed to weapons might want to take steps to divest from those companies too. Then there are arms and defense companies, and companies that invest in guns and weapons, to consider.

Retailers like Walmart—which sells a lot of guns, though those sales make up a small portion of its total revenue, per Morningstar—are much more likely to be in your standard index fund. Everyone has to work out on their own where they draw the line. (Also worth considering: Is divesting from these retailers enough, or should consumers also consider a boycott and stop shopping at these stores altogether?)

As Morningstar and others have pointed out, even if the funds you are invested have exposure to guns, they likely comprise a small part of the funds themselves. Walmart, for example, makes up less than 1% of the S&P 500.

Taking steps to divest from these kinds of funds could be considered a form of active investing, which financial planners usually advise against because people are generally bad at picking investments that pay off long-term, especially compared to a passive index. That said, if this issue is important to you, you might not care that you’re potentially missing out on some returns.

You can use a tool like As You Sow’s Gun Free Funds tool or Weapons Free Funds tool to see which companies your funds are invested in. Simply input the name of the fund, and the tool will should you what you’re exposed to. As You Sow also provides ratings of different funds‘ exposure to civilian firearms and weapons.

With a little research, it’s easy enough to avoid these stocks and funds when you’re investing primarily on your own, through a brokerage account or IRA. But if you mostly invest through an employer-sponsored 401(k), you’ll need to ask your plan administrator for different, gun-free funds in the future. It might seem like a long shot, but if enough employees make the request, employers may be willing to make the change.

“Meet with your friends, meet with your peers, talk with other employees about this,” says Behar. “Say you don’t want to own guns anymore. It sounds simple, and it is. It’s a matter of having that conversation.”

Does divesting work?

A common critique of divestment—or socially responsible investing in general—is that it doesn’t make a big impact. There is little evidence that a company’s share price changes as a result of divestment campaigns; for every investor who sells off shares of a company they find objectionable, there’s another one who has no issue with snapping them up as long as there’s the opportunity to make money.

But for some people, the desired outcome of divesting isn’t necessarily that these companies will go out of business or be forced into some kind of reckoning. Rather, it’s so that they can personally feel better about investments and ensure their spending aligns with their morals.

“It’s really a values situation,” says Behar. “If people don’t want to own these, just like divesting fossil fuels, it’s a statement that is very powerful.”

Of course, guns aren’t the only issue this touches, as Behar noted. There have long been funds that exclude so-called sin stocks, including firearms as well as tobacco and alcohol. In recent years, ESG funds—which focus on environmental, social, and governance factors—have exploded in popularity.

Aside from ESGs, business leaders in the U.S. are reexamining how their companies should interact with the politics and policies that affect their customers and employees.

Abortion rights have taken center stage in recent weeks, after the publication of a leaked Supreme Court draft opinion that would overturn Roe v. Wade. In Florida, the so-called “Don’t Say Gay” bill received pushback from constituents and companies like Disney. More and more corporations and CEOs are taking stances and dealing with the political repercussions of doing so.

For those who want to do something about America’s gun violence crisis, change won’t come overnight. Divesting is one place to start.

“We’re complicit in this world that we live in. We can’t just say, ‘Oh, I don’t like it,’ when we’re actively participating in it through our money,” says Behar. “There comes a point where we have invest in a future we want to live in.”