Calculate Profit/Capital Gains on Sold Inventory/Shares - excel

Question

I have a Google Sheet (Excel formulas apply) containing 2000 transactions that are structured like below:
Link to Google Sheet with example calcs here.
I need to calculate the Profit (ie. FIFO Capital Gains) for every sell order and place this amount in the 5th column (as pictured). This can be achieved with either traditional formulas or with a Google App Script. Preferably in Google Sheets.
I'm finding it difficult via formulas to match the sell order with the buy as you proceed down the table as some sell orders are split across multiple buy lines. If anyone could help with a formula or solution to tackle this problem it would be much appreciated. This is an updated question to the original here.

Answer 1

PRELIMINARY CONTEXT
Screenshot below refers:
Google sheets here
IMPORTANT UPDATE: re: 2000+ rows, see link in my last comment (for OneDrive template, s.t. expiry, and bottom of this proposal for screenshot of error "too large to import")
fyi: (Office 365 - Excel - fns. such as 'filter' etc., so #Name! will be ubiquitous upon opening this link; however, sharing this should serve as a convenient means to replicate above screenshot in the correct version of Excel)
REQUIREMENTS
Office 365
Adequate space to the right or ability to utilise extra sheet for calcs as req.
APPROACH
High-level | Take-aways
• Relies on 2 additional tables: Qty 'depletion' table (here - G:P) and corresp. Profit Vectors (here - R:Z)
• Compressed representations (2x2 tables, per Summary Tables, here: rows 19:32) could be explored to simplify matters (albeit these are still Work in Progress ['WiP'])
• VB could be attractive alternative too
Low-level | Procedural
Single-cell function could not be found without exceptional complication (however, suspect it could be possible e.g. using FilterXML?)
Qty label transposes filtered negative quantities (grey shaded, G3: J3)
These values are depleted in turn (from left to right, i.e. dependency on having data sorted in ascending order by date (in this depiction, data first sorted by 'fruit' as these are assumed to be independent in the context of the profit calc.)
For example, -5 quantity (G3) offset by +10 (B3) to yield +5 which, in turn contributes towards the -35 qty (H3) to yield -30. No further contribution can be made (left to right); next row (5): +20 avail (given), no offset against -5 (G3, already 'reimbursed', so 20 offset against -30 (H4) to yield -10, and so forth.
Worksheet set up to accommodate longer list of fruit / profits
Result table of residual 'quantities' (~ G:J) applied to price differential to yield 'profit vectors' (R:U) which are summed against corresponding negative quantities to produce Profit score (yellow shaded cells)
FUNCTIONS
Salient functions (all of which should be available within Google Sheet, but for completeness):
1) Profit calc. (E4, drag down):
=IF(B4<0,SUM(INDEX($R$4:$AA$13,0,MATCH(A4&C4,$R$2:$AA$2&$R$3:$AA$3,0))),"")
This can be dragged down / to right as far as desired (in this case, goes to: Z13)
2) Qty table - contents (G4)
=IF($A4=G$2,IF(G$3<>"",IF(G$2=E$1,IF($B4<0,IF(G3<0,G3,0), IF(E4<0,0,E4)+IF(G3<0,G3,0)), IF(G$3<>"", IF($B4<0,IF(G3<0,G3,0),$B4 + IF(G3<0,G3,0))))),G3)
3) Qty table - headers (G2, G3 resp.)
=MID(TRANSPOSE(FILTER(A4:A13&B4:B13,B4:B13<0)),1,SEARCH("-",TRANSPOSE(FILTER(A4:A13&B4:B13,B4:B13<0)))-1)
=-1*MID(TRANSPOSE(FILTER(A4:A13&B4:B13,B4:B13<0)),SEARCH("-",TRANSPOSE(FILTER(A4:A13&B4:B13,B4:B13<0)))+1,LEN(TRANSPOSE(FILTER(A4:A13&B4:B13,B4:B13<0))))
Drag to right as far as desired / able to (this case have been dragged to col. P)
4) Profit table - contents (R4, drag down/right)
=IF(R$2<>"",IF(G3>0,0,IF(G4>0,ABS(G3),G4-G3))*(R$3-$C4),"")
5) Profit table - headers (R2, R3 resp.):
=MID(TRANSPOSE(FILTER(A4:A13&"-"&$C$4:$C$13,B4:B13<0)),1,SEARCH("-",TRANSPOSE(FILTER(A4:A13&"-"&$C$4:$C$13,B4:B13<0)))-1)
=1*MID(TRANSPOSE(FILTER(A4:A13&"-"&$C$4:$C$13,B4:B13<0)),SEARCH("-",TRANSPOSE(FILTER(A4:A13&"-"&$C$4:$C$13,B4:B13<0)))+1,LEN(TRANSPOSE(FILTER(A4:A13&"-"&$C$4:$C$13,B4:B13<0))))
MISC
Alternate solutions derived & explored include triangular frameworks
(rows 17-32).
These tabulate the interaction between values assoc.
with positive and negative quantities positive/negative quantities
(and corres. dates)
Should be noted these are otherwise unnecessary (in terms of functions, previous 'section'
Continuing in the same vein as before....
6a) 1st summary table (Qty): row and col headers (A22 - drag down, C19 - drag right resp.):
=FILTER(D4:D13,1*IF($A$21="*",1,(A4:A13=$A$21))*(B4:B13<0))
=TRANSPOSE(FILTER(D4:D13,1*IF($A$21="*",1,IFERROR((A4:A13=$A$21),1))*(B4:B13>0)))
6b) 1st summary table (Qty): running total (c19, drag down / right as req., in this case: to P19)
=SUM($C21:C21,$B22#)
6c) 1st summary table (Qty): content (c22, drag down or tonight as req.)
=IF(OR(C$20="",$A22=""),"",IF($A22>C$20,MAX(0,C21+MIN(0,SUM($B22:B22))),C21))
7) 2nd summary table (Profits): C29, not draggable
=MIN(C$21,C$21+$B22)*($B29-C$28)
Note; other features of 2nd summary table (row / col headers) follow from 1st. Also, placing '*' in the fruit selection cell (A21) returns all (this is still WiP as mentioned previously).
SCREENSHOTS FOR LARGER UPLOAD: