study(title="zzz Coinbase XBTUSD Premium", overlay=false)

cb=security("COINBASE:BTCUSD", period, close)

mex=security("BITMEX:XBTUSD", period, close)


futs = cb-mex
cClr = futs>0 ? green : red
hline(10, linestyle=dotted)
hline(-10, linestyle=dotted)

hline(25, linestyle=dashed)
hline(-25, linestyle=dashed)

plot(futs, title="Futures", color=cClr, style=columns, transp= 40, linewidth=3)