Launch HN: Double (YC W24) – Index Investing with 0% Expense Ratios

Hi HN, we’re JJ and Mark, the founders of Double ( https://double.finance ). Double lets you invest in 50+ broad stock market indexes with 0% expense ratios. We handle all the management, including rebalancing and tax-loss harvesting—proactively selling losing stocks to potentially save on taxes—for $1/month. Our goal is to bring the low fee trend pioneered by Robinhood to ETFs and mutual funds. We posted a Show HN about 3 months ago ( https://news.ycombinator.com/item?id=41246686 ) and since then have crossed $10M in AUM (Assets Under Management) [1]. Here’s a demo video: https://www.loom.com/share/10c9150ce4114f278e8c249f211e7ec8 . Please note that none of this content should be treated as financial advice. Everyone knows that fees eat into your investing returns. Financial advisors generally charge 1% of AUM per year, and ETFs have a weighted average expense ratio of about 0.17%, although some go as low as 0.03% for VOO. Over a 30-ye