Under the hood
The initial setting is to for monthly data (you can change that on the Control Panel or Wizard Settings), so SignalSolver will request monthly stock price data from Yahoo. Several Web queries are made, one for the price data, then up to 10 others for the dividend data, the splits data, spin-off data and possibly another for additional splits information depending on how the price data looks. Price, dividends and splits info comes from Yahoo, spin-off and additional splits info comes from Morningstar.
Splits, Dividend and Spin-off correction
SignalSolver parses the price data into spreadsheet format. It then reads the spin-offs which are handled a special way to ensure that no step changes are caused in the prices. Any dividends and splits reported on spin-off days are over-ridden and ignored. The date of each event is checked to see if the open prices are impacted and if so they are corrected. Prices are then corrected for splits, but not dividends. Dividends are handled by the backtester
Other corrections to price data
With the exception of price gaps (which were quite common in the 2008-9 crisis), the following corrections/flags are unusual, but they should always be looked into.
- Periods with any zero in the price or volume are skipped
- Date gaps of 5 days or more (daily), 9 days or more (weekly), 35 days or more (monthly) are flagged
- Any price gaps of 100% rise or 5o% drop are flagged
- Duplicate dates are flagged
- Highs and Lows are set to the highest and lowest price reported on each day.