Prices are split- and dividend-adjusted (total return); using raw closes would understate income stocks. Buys happen on each month's last trading day at that day's adjusted price, split by your target weights — this models dollar-cost averaging, not rebalancing. The SPY line receives exactly the same cash on the same days. Survivorship caveat: delisted companies are not in our price set, which flatters any strategy tested only on today's tickers. Past performance is not investment advice.