A tax on Wall Street trading would probably end up hurting Main Street investors too, according to an advocacy group for high-speed traders.

A financial-transaction tax proposed by U.S. Senator Bernie Sanders would deal a “major blow” to retirement and pension funds, university endowments, retirees and families saving for college, the Modern Markets Initiative said in a report released Thursday. For example, a person with $100,000 invested in a 401(k) over 40 years could expect to pay $64,200 in taxes over that period if a levy on trading is implemented, the group estimated.

“The financial-transaction tax would have a devastating impact on investors across the board,” Modern Markets Initiative Chief Executive Officer Kirsten Wegner said in an interview. “This is a retirement tax that is going to hit everyone who invests” by reducing market liquidity and making it more expensive to trade, she said.

The report is the latest in the industry’s long-running fight against such proposals. Many high-frequency trading firms list a financial-transaction tax as a significant risk to their business model.

Sanders and Senator Elizabeth Warren, another critic of Wall Street, will face off against other Democratic presidential candidates for a debate in Houston on Thursday. Analysts have warned that the Sanders plan -- which would pay off student debt by levying a tax on trading -- could make markets more volatile, with the costs ultimately borne by American households.

 This article was provided by Bloomberg News.