On Sun, Nov 1, 2020 at 8:40 PM Aaron Lindsay <[email protected]> wrote:
> On Saturday, October 31, 2020 at 4:38:28 PM UTC-4 [email protected] wrote: > >> On Sat, Oct 31, 2020 at 4:09 PM Aaron Lindsay <[email protected]> wrote: >> >>> Hello! >>> >>> I have a scary accounting question for Halloween... >>> >> >> oooOOOoOOoOoOoOOoO >> >> >>> >>> I have 8 years of GnuCash data I'd like to convert to beancount. The >>> problem is that, as far as I can tell, GnuCash doesn't track cost basis for >>> trades. Because of that, I'm having difficulty replicating the suggested >>> approach from >>> https://beancount.github.io/docs/trading_with_beancount.html. I am >>> using https://github.com/falsifian/gnucash-to-beancount and can >>> 'successfully' convert my data to beancount, but instead of specifying the >>> cost basis, purchases of investments end up looking like: >>> >>> 2014-10-31 * "BUY 1 SPY @ 200" >>> Assets:Current-Assets:Brokerage:SPY 1 SPY @ 200 USD >>> Assets:Trading:CURRENCY:USD 200 USD >>> Assets:Current-Assets:Brokerage -200 USD >>> Assets:Trading:NYSE:SPY -1 SPY @ 200 USD >>> >> >> Urg... >> This should be an improvement (despite the absence of cost basis): >> >> 2014-10-31 * "BUY 1 SPY @ 200" >>> Assets:Current-Assets:Brokerage:SPY 1 SPY @ 200 USD >>> >> Assets:Current-Assets:Brokerage -200 USD >>> >> >> Also, I'd create a cash sub-account for the cash portin. >> >> Sales are in essentially the same form, just in reverse. In this way, my >> Assets:Trading:CURRENCY:USD >>> account ends up being a weird combination >>> >> >> It's the aggregate P/L (without discounting commissions). >> > > Isn't it only the aggregate P/L *after* I sell all positions? Otherwise it > also includes the cash used to buy my currently-held investments. Or maybe > I'm confused about the definition of "aggregate P/L"? > Well you're inserting a corresponding cash amount on your buys too. That original transaction is essentially applying the currency trading accounts method but for your shares. Basically, what that is going to reflect, is the total amount of cash against all positions outstanding. You could compute your P/L by subtracting that from the sum total of the position values. So technically no, it's not just your P/L, it's all the cash you used to acquire the positions + realized P/L from already sold ones, which piles up in that account. It doesn't matter; it's overly complicated. Just use the cost basis notation. of the total cost basis of all my current investments and the gains or >>> losses from previous investments. Obviously I have enough data here to >>> calculate the cost basis for *purchases* of investments, >>> >> >> Yes, something like this: >> >> 2014-10-31 * "BUY 1 SPY @ 200" >>> >> Assets:Current-Assets:Brokerage:SPY 1 SPY {200 USD} >>> Assets:Current-Assets:Brokerage:Cash -200 USD >>> >> > Yup, that's exactly what I was thinking of doing. And I think I've got > gnucash-to-beancount doing that for me now. > +1 > > so that ought to be do-able with some modification of the >>> gnucash-to-beancount scripts, but I'm not sure how best to handle the >>> sales. I've been reading the beancount documentation and have found the >>> "FIFO" booking method - is that pretty much my only option at this point? >>> Are there any gotchas to using it in my case? >>> >> >> You could use that, but it's not necessarily going to match the P/L you >> declared in the past for each period (though the total P/L should be >> right). Personally I would gather my history and then try to manually match >> each of the sales, but I'm a maniac. bean-doctor context can help, by >> printing the available lots just before a transaction. >> >> How many sales do you have? >> > > To be honest, I haven't been tracking my P/L much, if at all. Though I'm > even a little unclear on how GnuCash would derive P/L given the 'Trading' > account setup it uses - how are you assuming GnuCash calculates P/L when > you say it's not going to match beancount's? > It depends if it stores the realized gains in another account. What you wrote originally above is a way to keep track of cash vs. positions in order to be able to derive P/L, e..g, I spent $1000 to buy 2 shares, then $600 to buy one more, now I have -$1600 and 3 shares, and so if I want to compute P/L, say the price per share is $650, the P/L is then 3x$650 - $1600. When you realize gains, do you keep the profits in that account? If so, the P/L is going to be that over all time. If instead the realized P/L gets moved to another account (I would suggest to do that, to be able to break it apart), then it's the P/L of only the open positions. (BTW, this is precisely how you keep track of open positions in a trading strategy with a very large number of transactions; this is the correct way, as it is compressed (small in size) and the sums have interpretable meaning.) Assuming they're all recorded in a consistent form (which I'm not sure I > believe), I have around 200 sales. I think I will probably end up letting > bean-count do its best using "FIFO" and go back behind it and check up on > the ones that I can find data for. > Yeah, it's borderline. You could also try to automate it, by analyzing the different instruments. Your 200 trades are probably distributed over many stocks, so it's possible it might be pretty easy to match them up manually because the number of possible lots to match against might be small, with the help of a little script. As a bonus - if I end up using the "FIFO" booking method, is it possible to >>> get beancount re-write my .beancount file with the cost basis it calculated >>> internally for the sales? >>> >> My goal there would be to make the implicit cost basis on sales explicit >>> - and allow me to use STRICT moving forward without having to manually fix >>> up 8 years of transactions. >>> >> >> Yes. Just "bean-query print" your ledger and it will print out everything >> explicitly. >> >> I hope this helps, >> > > It does, thanks! > > -Aaron > > Thanks for any pointers! >>> >>> -Aaron >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Beancount" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/beancount/01dd4feb-9b9a-423b-bbee-d7a9d2613035n%40googlegroups.com >>> <https://groups.google.com/d/msgid/beancount/01dd4feb-9b9a-423b-bbee-d7a9d2613035n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "Beancount" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beancount/f3419875-8c5a-482b-b74e-5c2b157216a6n%40googlegroups.com > <https://groups.google.com/d/msgid/beancount/f3419875-8c5a-482b-b74e-5c2b157216a6n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Beancount" group. 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