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 ha...