Searching in database of shares

Hello here,
First of all I would like to apologize for my english.
EDIT: When I have cell(A1=523) Is there any way how to type in A2 something like that =max(A(A1):A1263) = max(A523:A1263)

Anyway...I have a databes of values. These values are not and cannot be sorted ascending or descending order.
Something like that:
1....10
2....9,8
3....9,5
4....8,4
5....9,75
6....9,3
7....8,9
8....8,1
9....7,6
10...7,2
etc

I wanna select the command (stop sell %) for exmaple 10%. It means when thae value drops by 10% (90% from 10 = 9) tell me the date(number(1,2,3,4....) so restult would be 4.
Next step: From (4....8,4) same command continues...when value drops by 10% ( 90% from 8,4 = 7,56) tell me the number when it happend....result would be 10..
etc etc..like 10x
is that even possible how to do it with formulas? I have no experience with programming(VBA)

I am using command for values higher than first :INDEX($AB$151:$AB$1263;MATCH(A1;$AC$151:$AC$1263;-1))-1; but it find just 1st value when it reachs but I have to found for example 2nd value if you know what I mean

for values lower than first: INDEX($AB$151:$AB$1263;MIN(WHEN($AC$151:$AC$1263>=A1;ROW($AC$151:$AC$1263)-ROW($AB$151)+1
it allways find 1st value

I would very appreciate any help. Thx!