hledger/hledger/Hledger/Cli/Commands/Roi.txt
2021-03-07 10:25:08 -08:00

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roi
Shows the time-weighted (TWR) and money-weighted (IRR) rate of return on
your investments.
_FLAGS
At a minimum, you need to supply a query (which could be just an account
name) to select your investment(s) with --inv, and another query to
identify your profit and loss transactions with --pnl.
If you do not record changes in the value of your investment manually,
or do not require computation of time-weighted return (TWR), --pnl could
be an empty query (--pnl "" or --pnl STR where STR does not match any of
your accounts).
This command will compute and display the internalized rate of return
(IRR) and time-weighted rate of return (TWR) for your investments for
the time period requested. Both rates of return are annualized before
display, regardless of the length of reporting interval.
Price directives will be taken into account if you supply appropriate
--cost or --value flags (see VALUATION).
Note, in some cases this report can fail, for these reasons:
- Error (NotBracketed): No solution for Internal Rate of Return (IRR).
Possible causes: IRR is huge (>1000000%), balance of investment
becomes negative at some point in time.
- Error (SearchFailed): Failed to find solution for Internal Rate of
Return (IRR). Either search does not converge to a solution, or
converges too slowly.
Examples:
- Using roi to compute total return of investment in stocks:
https://github.com/simonmichael/hledger/blob/master/examples/roi-unrealised.ledger
- Cookbook -> Return on Investment
Semantics of --inv and --pnl
Query supplied to --inv has to match all transactions that are related
to your investment. Transactions not matching --inv will be ignored.
In these transactions, ROI will conside postings that match --inv to be
"investment postings" and other postings (not matching --inv) will be
sorted into two categories: "cash flow" and "profit and loss", as ROI
needs to know which part of the investment value is your contributions
and which is due to the return on investment.
- "Cash flow" is depositing or withdrawing money, buying or selling
assets, or otherwise converting between your investment commodity
and any other commodity. Example:
2019-01-01 Investing in Snake Oil
assets:cash -$100
investment:snake oil
2020-01-01 Selling my Snake Oil
assets:cash $10
investment:snake oil = 0
- "Profit and loss" is change in the value of your investment:
2019-06-01 Snake Oil falls in value
investment:snake oil = $57
equity:unrealized profit or loss
All non-investment postings are assumed to be "cash flow", unless they
match --pnl query. Changes in value of your investment due to "profit
and loss" postings will be considered as part of your investment return.
Example: if you use --inv snake --pnl equity:unrealized, then postings
in the example below would be classifed as:
2019-01-01 Snake Oil #1
assets:cash -$100 ; cash flow posting
investment:snake oil ; investment posting
2019-03-01 Snake Oil #2
equity:unrealized pnl -$100 ; profit and loss posting
snake oil ; investment posting
2019-07-01 Snake Oil #3
equity:unrealized pnl ; profit and loss posting
cash -$100 ; cash flow posting
snake oil $50 ; investment posting
IRR and TWR explained
"ROI" stands for "return on investment". Traditionally this was computed
as a difference between current value of investment and its initial
value, expressed in percentage of the initial value.
However, this approach is only practical in simple cases, where
investments receives no in-flows or out-flows of money, and where rate
of growth is fixed over time. For more complex scenarios you need
different ways to compute rate of return, and this command implements
two of them: IRR and TWR.
Internal rate of return, or "IRR" (also called "money-weighted rate of
return") takes into account effects of in-flows and out-flows. Naively,
if you are withdrawing from your investment, your future gains would be
smaller (in absolute numbers), and will be a smaller percentage of your
initial investment, and if you are adding to your investment, you will
receive bigger absolute gains (but probably at the same rate of return).
IRR is a way to compute rate of return for each period between in-flow
or out-flow of money, and then combine them in a way that gives you a
compound annual rate of return that investment is expected to generate.
As mentioned before, in-flows and out-flows would be any cash that you
personally put in or withdraw, and for the "roi" command, these are the
postings that match the query in the--inv argument and NOT match the
query in the--pnl argument.
If you manually record changes in the value of your investment as
transactions that balance them against "profit and loss" (or "unrealized
gains") account or use price directives, then in order for IRR to
compute the precise effect of your in-flows and out-flows on the rate of
return, you will need to record the value of your investement on or
close to the days when in- or out-flows occur.
In technical terms, IRR uses the same approach as computation of net
present value, and tries to find a discount rate that makes net present
value of all the cash flows of your investment to add up to zero. This
could be hard to wrap your head around, especially if you haven't done
discounted cash flow analysis before. Implementation of IRR in hledger
should produce results that match the XIRR formula in Excel.
Second way to compute rate of return that roi command implements is
called "time-weighted rate of return" or "TWR". Like IRR, it will also
break the history of your investment into periods between in-flows,
out-flows and value changes, to compute rate of return per each period
and then a compound rate of return. However, internal workings of TWR
are quite different.
TWR represents your investment as an imaginary "unit fund" where
in-flows/ out-flows lead to buying or selling "units" of your investment
and changes in its value change the value of "investment unit". Change
in "unit price" over the reporting period gives you rate of return of
your investment.
References: * Explanation of rate of return * Explanation of IRR *
Explanation of TWR * Examples of computing IRR and TWR and discussion of
the limitations of both metrics