Arbitrage v1.0
This is a simple tool to indicate arbitrage opportunities between TWO markets. Base currency must be the same for both markets. Arbitrage signal and minimum market spread uses percentage, base currency or both. Spread input accepts increments as small as 0.00000001. Works best with smaller time frames.

I will develop this further if enough people show an interest.
Open-source script

In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.

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Want to use this script on a chart?
 
// This is a simple tool to indicate arbitrage opportunities between two markets. 
// Base currency must be the same for both markets. 
// Arbitrage signal and minimum market spread uses percentage, base currency or both. 
// Spread input accepts increments as small as 0.00000001. Works best with smaller time frames.

study(title="Arbitrage", shorttitle="Arb1.0", overlay=false)
spread = input(10,step=0.00000001,title="Spread $")
spreadpct = input(5,step=0.00000001,title="Spread %")/100
sym1 = input("BTCUSDT",title= "Symbol 1")
sym2 = input("COINBASE:BTCUSD",title= "Symbol 2")
source = close
sym11 = sym1, res11 = period
sym22 = sym2, res22 = period 

s1 = security(sym11, res11, source)
s2 = security(sym22, res22, source)

sym33 = s2-s1
aaa=(s2/s1)-1
bbb = aaa*100
plot(sym33, color=sym33>0?green:red, linewidth=2,style = columns,title="$",transp=60)
plot(bbb, color=bbb>0?teal:orange, linewidth=2,style = columns,title="%",transp=100)

bgcolor(abs(sym33)>=spread?purple : na, transp=40,title = "Spread $")
bgcolor(aaa>=spreadpct?yellow : na, transp=100,title = "Spread %",transp=100)