(Bloomberg) -- Sofia Massie left her job at Jane Street in January with one thing: an idea for an ETF that would mirror the US stock market but quietly hold onto dividends, wringing out a tax advantage many investors never see.She didn’t have a team. Or a brand. Or the institutional heft that usually comes with a Wall Street-backed launch. What she did have was about $300,000 — and a white-label firm to handle the mechanics. Eight months later, the LionShares US Equity Total Return ETF (TOT) went live.Massi ...