The Republican from Oshkosh is one of the wealthiest members of the Senate. And he’s heavily invested in the stock market.

Sen. Ron Johnson was estimated to have a net worth of about $39 million by Open Secrets in 2018, according to the money-in-politics-tracking nonprofit’s most recent evaluation. That would make him the country’s 6th-richest senator.

By comparison, Democrat Tammy Baldwin, the other senator from Wisconsin, had a net worth of about $1.1 million in 2018, Open Secrets estimated. The median senator was estimated to be worth about $1.7 million in 2018.

Johnson was wealthy before he joined the Senate. Open Secrets estimated his net worth in the multi-millions in 2009, the year prior to his first run.

On his most recent financial disclosure report, for calendar year 2022, which you can read below, Johnson claims between $5 million and $25 million in the SPDR S&P 500 ETF trust, or SPY, a low-cost, commonly-owned index fund designed to track the S&P 500 stock market index. The fund’s top holdings, moving down from the highest percentage, include Apple, Microsoft, Amazon, NVIDIA, Alphabet (Google’s parent company), Tesla and Meta (Facebook’s parent company).

A U.S. senator makes an annual salary of $174,000.

Johnson also reports between $5 million and $25 million in a Charles Schwab money market account.

And he reports commercial real estate holdings, again in the range of $5 million to $25 million.

His full disclosure report is below.

The STOCK Act of 2012, which passed both the House and Senate with near-unanimous votes, banned House members and aides from using nonpublic information derived from their positions to trade stocks. It also requires the House clerk to post members’ financial disclosure reports filed online.

But it does not ban politicians from owning stock in individual companies, as many have insisted. A bill introduced last month in the Senate by Kirsten Gillibrand (D-New York) and Josh Hawley (R-Missouri) would do that. It faces an uncertain path forward.

The Badger Project is a nonpartisan, citizen-supported journalism nonprofit in Wisconsin.