How to Compare Online Brokers' Commissions

Are you trying to save money on your tradingget a slightly better price than the one you specify
commissions by considering a new online broker? Ifon limit orders at least some of the time. If I had to
so, then you'll need to sit down and compare theirguess, I'd say that Thinkorswim gives me price
plans in a practical way.improvement on one out of three stock trades -
Here's how I would do the math:pretty good. On options trades, it happens
I would start out with my trading results from 2009.occasionally - not nearly as often as I'd like.
I'd be looking at my profit & loss numbers forIf you never get price improvement, then you can
the year, and what I paid in commissions.do better elsewhere.
Let's say my profit for the year was $20,000, andSo how can you calculate the potential effect of
that I paid $1000 in commissions on 100 stock tradescrappy executions? Here's one way, albeit a rough
($10 per trade). Note: I'm using round numbers hereone:
to keep it easy.Take your trading results for 2009, and subtract a
If potential new online broker X charges $8 a trade -minuscule amount - 0.2% or less.
I'd save $2 a trade times, 100 trades. That's $200.Then, randomly select a few of your trades from
But is it enough to move the needle? After all, that2009, and do the following to your profit or loss on
would improve my profits for the year by just 1%each: hurt your results by 5%. Either add 5% to your
($200 divided by $20,000). That's not worth switchingloss or reduce your profit by 5%. This is intended to
for - unless you are experiencing customer-servicesimulate the impact of the broker not being able to
hassles.get your most important trades done during busy
On the other hand, if you make 1,000 trades a yearperiods.
and could save $5 a trade, you'd save $5,000. ThatTake these numbers, and factor them into your
could feed a family for a year And if you're aestimates on how a new online broker impacts your
megatrader moving thousands of trades a month,P&L. If you'd save $300 on commissions with a
the savings could easily go into the six figures.possible $50 negative impact on the execution side,
So for active traders, the decision may seem prettyyou really have no reason to switch unless you are
easy - go for a cheaper broker because they savingsdissatisfied with customer service, or are getting hit
could be meaningful.with silly service charges.
However, there are other issues to consider, likeIf it seems like I'm overemphasizing customer
execution quality. Will your trades be completed in aservice, it's because I am. Customer service should
timely fashion at the best possible prices?be your number-one concern when choosing an online
This is a tough issue to figure out, especially when itbroker. Fancy charting packages and cheap
comes to highly-liquid markets like equities wherecommissions are great on their own - but you won't
orders can be placed and filled in the blink of an eye.care about them if you're left on hold for 45 minutes.
My rule of thumb is that on stock orders, you should