Backtest Data & Assumptions
FWB strategies are based on weekly open and close data on the S&P 500 index (GSPC) from January 2, 1928 through present. If the weekly opening price is not provided for a week in history, we assumed the prior week’s closing price for the next week’s open price. However, we actually take positions in VOO (Vanguard 500 ETF) because of its low cost expense structure and its close tracking of the S&P 500 index.
We assume that all dividends received are reinvested.
We use current and historic valuation data from Robert Shiller.
Taxes, commissions, fees, and interest are not included.
Hypothetical back testing results give no consideration to taxes because we only use this in our retirement accounts. Using this strategy in a taxable brokerage account will result in worse performance due to taxes.
Trading commissions and fees are also not considered in the back testing hypothetical results, and will decrease your rate of return accordingly. However, interest earned on cash deposits when we sell and temporary sit out of the market are also not included and would increase your returns.
While these assumptions are imperfect, they are consistently applied across the entire back test time frame from January 2, 1928 through present and are the same ones we use today for consistency. The trading signals each Saturday are based on weekly closing data and various calculations derived from this data. The exact formulas and buy/sell trigger levels are proprietary and not shared publicly. The trading signals are mechanically followed in all back testing since January 2, 1928 through present with no human discretion or adjustment.