indicator("example")
btc     =       request.security("INDEX:BTCUSD",    "D",close)
sol     =       request.security("CRYPTO:SOLUSD",   "D", close)
btcPriceChange   = btc      -   btc[90]
solPriceChange   = sol      -   sol[90]

btcPercentageChange   = (      btcPriceChange      /      btc[90]     ) * 100
solPercentageChange   = (      solPriceChange      /      sol[90]     ) * 100

AveragePercentChange = math.avg(btcPercentageChange,solPercentageChange)
plot(AveragePercentChange)