The Wall Street Journal’s Richard Rubin says Elizabeth Warren’s proposed taxes could claim more than 100% of income for some wealthy investors. Here’s an example Rubin discussed Friday:

“Consider a billionaire with a $1,000 investment who earns a 6% return, or $60, received as a capital gain, dividend or interest. If all of Ms. Warren’s taxes are implemented, he could owe 58.2% of that, or $35 in federal tax. Plus, his entire investment would incur a 6% wealth tax, i.e., at least $60. The result: taxes as high as $95 on income of $60 for a combined tax rate of 158%.”

In Rubin’s back-of-the-envelope analysis, an investor worth $2 billion would need to achieve a return of more than 10% in order to see any net gain after taxes. Rubin notes that actual tax bills would likely vary considerably depending on things like location, rates of return, and as-yet-undefined policy details. But tax rates exceeding 100% would not be unusual, especially for billionaires.