# implementation plan
## Given info
```
symbols: [world, mid cap, reit, 500, small cap, bond]
desired %: [25, 10, 5, 35, 10, 15]
current $: []
yield %: [2.6, 1.3, 4.4, 1.7, 1.2, 2.6]
```
shares-per-account: []
free cash per account (roth, ira, taxed)
total funds = sum(free cash) + sum(invested)
delta $ per ETF: [desired - invested foreach ETF]
delta shares per ETF: [delta/share price foreach ETF]
## ideas for allocation
* put higher yield ETFs into tax-advantaged accts
* keep most rebalancing in tax-advantaged accts
* this means some of each fund needs to be tax sheltered
* do as little as possible (minimize # transactions from current state)
assign primary allocations:
```
15% roth -> bond, 1/2 reit
30% ira -> foreign, 1/2 reit
55% taxable -> us small, us mid, 500
```
10% of each account should mirror portfolio, to ease rebalancing
* TODO: how to test this over time?
## Iterative algorithm
```
for each ETF:
if we're overweight, sell shares
- from a sheltered account first
- TODO: when okay to sell from taxable account?
for each account:
make sure that there's at least 10% * desired % of each ETF
-only buy shares if there's: free cash && we need shares
for each primary allocation:
buy shares in acct until one of
- we don't need more
- account has no more free cash
for each share we still need more of, sorted by yield:
fill tax advantaged accounts with shares
fill taxable accounts
```