Slow Index or Match function in large data set

Hi all,

I encounter a problem with index or match function perform very slow in large data set

I am using excel to do optimisation for trading.
I am building moving average for price with

the formula i am using does not contain volatile behavior (with my limited knowledge i guess), below are the potential function causing the slow calculation

=AVERAGE(INDEX($F$1:$F$20795,E179-$G$1+1):F179) , got 3 columns each with 20k data using this formula
=MATCH("Cross down",M177:M20871,0), 1 column with 20k data using this formula
=IF(K183=1,INDEX(N184:O20878,N184,2),0), 1 colum with 20k data with this formula


The result of the worksheet will be calculated with changing variable the the final result is copy and paste into another sheet. All this is done by my own VBA code

The speed is really slow when i perform this.

Please help to solve the speed issue

Thank you~~~~~

Attached part of the workbook i am doing here

Remark to note
Initially, i was using Offset and vlookup to handle the result i want, as they are volatile, it is quite slow
Then i replace them with index and match, but it get even slower

Something to mention is when using offset and vlookup to do the job, every core of cpu is running with 100%
after changing to index and match, speed drop and only 12%+- of cpu being utiliesed.

I understand vba is single threaded process , but it is confusing as when i was using offset and vlookup to run the vba, it utiliese every core, then when change to index and match, it is slower and seem like using a core or two

A discover from other excel help site is that thee delay of my issue is due to smart recalculation of excel that it took a bit of time to establish the logic tree, by turning it off through vba fullforce calculation do help to solve the lag of my issue
but it make whole workbook volatile, end up no different compare to using offset and vlookup

Guess this is what it is