Add the SP500 ttm Earnings Yield Spreads vs the 3 Month and 10 Year Treasury Rates.
Short Spread = SP500 E/P ttm - 3 Month Treasury Rate
Long Spread = SP500 E/P ttm - 10 Year Treasury Rate
Symbol "SP500_EARNINGS_YIELD_MONTH" as the SP500 Earnings Yield
Symbol "US03MY" as the 3 Month Treasury Rate
Symbol "US10Y" as the 10 Year Treasury Rate
Based on research...