As said, this is important to note that there is no co-relation between your portfolio picks. It seems what I use among the ETF and currencies, this appears to be assumed to have assets not correlated. If you use the portfolio optimization techniques I use, it measures variance and volatility. It seems to be wise to try.
As you read these article below, there is a way to get a range of -1 to +1 to measure correlation.
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