Imagine a variable history exist that contains COST/PROCEEDS
These Cost/proceeds will be ccalled C_1, C_2, ..., C_n

Imagine we are using ARK coin

For elements in history:
	Search for last Cost/Proceeds which we will denote C1
	if C1 is positive:
		Store value of index for "last element"
		Search for next C_n that is a sell
		if found
			index-1 is the beginning of our interval
	if C1 is negative:
		Last value index is last eleemnt of the interval
		Find last sell, take index-1 as beginning of interval


	return sum of C_1 to C_n