Based on my previous script "BTC Contango Index" which was inspired by a Twitter post by Byzantine General:
This is a script that shows the contango between spot and futures volumes of Bitcoin to identify overbought and oversold conditions. When a market is in contango, the volume of a futures contract is higher than the spot volume. Conversely, when a market is in backwardation, the volume of the futures contract is lower than the spot volume.
The aggregate daily volumes on top exchanges are taken to obtain Total Spot Volume and Total Futures Volume. The script then plots (Total Futures Volume/Total Spot Volume) - 1 to illustrate the percent difference (contango) between spot and futures volumes of Bitcoin. This data by itself is useful, but because aggregate futures volumes are so much larger than spot volumes, no negative values are produced. To correct for this, the Z-score of contango is taken. The Z-score (z) of a data item x measures the distance (in standard deviations StdDev) and direction of the item from its mean (U):
Z-score = (x - U) / StDev
A value of zero indicates that the data item x is equal to the mean U, while positive or negative values show that the data item is above or below the mean (x Values of +2 and -2 show that the data item is two standard deviations above or below the chosen mean, respectively, and over 95.5% of all data items are contained within these two horizontal references). We substitute x with volume contango C, the mean U with simple moving average ( SMA ) of n periods (50), and StdDev with the standard deviation of closing contango for n periods (50), so the above formula becomes: Z-score = (C - SMA (50)) / StdDev(C,50).
When in contango, Bitcoin may be overbought.
When in backwardation, Bitcoin may be oversold.
The current bar calculation will always look incorrect due to TV plotting the Z-score before the bar closes.