text: edited Aug 4, 2017 at 16:34
  asked Aug 30, 2011 at 23:00
  This is what I actually meant to ask: bitcoin.stackexchange.com/questions/569/… I'll accept the answer to the current question because it sort of answers the letter of what I asked, if not the intent.
  Sep 4, 2011 at 23:09
  edited Mar 7, 2012 at 18:37
  answered Aug 30, 2011 at 23:06
  I'm not sure whether this counts as "efficient."
  Aug 30, 2011 at 23:11
  It is as efficient as is possible. Given that you should not trust anyone else's tools to do it.
  It is also worth pointing out that the more "efficient" the market gets, and the easier it becomes to arbitrage, the less opportunities there will be for such a thing. You should be aware that in any arbitrage play, you can get "stuck" if one of the exchanges is not as liquid as you thought it was going to be.
  The only problem with this approach is that you eventually wind up jammed, with coins in the wrong place. Fortunately, if they're bitcoins, you can pretty easily move them. But if it's cash, it can take you quite some time to move it from one exchange to another. If one exchange is consistently higher than another, you are quite likely to get jammed a lot.
  Its possible and most likely to happen with small and inactive exchanges. But the low volume traded there also limits the profit, as even a small pair of transactions will level the prices to near equality and no profit.