Saturday, November 13, 2010

Tacc - fstats


If you have a portfolio called Equities, you can obtain the
performance using the command:
tacc-0.1> fstats Equities
You can obtain the performance of several accounts together, e.g. Eq1
and Eq2, using
tacc-0.1> fstats { Eq1 Eq2 }

Typical output is something like:
CRR% 6 IRR% 10 PROFIT 1000.00
This tells you that the profit you made (realised+unrealised) is
1000.00, and the interal rate of return you are making is 10%. IRR is
"a true compound rate of return" - which I think is the most
meaningful way of measuring the performance of a portfolio. It does
suffer from some theoretical weaknesses; but to me, it is the most
sensible statistic available.

The CRR figure is a bit of a home-brew statistic, which measures the
"current rate of return". All it does is apportion the IRR according
to the current date. So, if, for instance, the Dow is up 2% for the
current calendar year, you can see that you are currently beating the
index by 4% (6-2).

My goal in TACC is to be able to massage the data produce by
ledger-cli (it sometimes has a little quirky behaviour), and be
extensible. I think of it as being like John's REPL for v3, but fully
programmable.

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