Topic: Bitstamp TX Fee Exploit - Fee 1.16% instead of 0.2% [Bitstamp Fixes on May 15th] (Read 21168 times)

Well this is quite surprising....In a way. Then again, it really shouldn't...

Hello Bitcointalk community,

I have been around as a visitor for a while and registered only today. I learned a lot from this community about Bitcoin, so thanks a lot! I hope it's not against any rules to post in a year old thread as a noob (who is getting familiar with trading only since a short while.)

I just stepped into this "fee trap" at Bitstamp and like to ask if someone has experience with  trading on Bitstamp and could explain why on earth would a bot want to split my sell order of 0.1 BTC into five small buys ? The buyer also has to pay fees for each buy, and due to the rounding of fees pays more than what's listed in the fee schedule.

BTC   USD   Price   FEE
-0.020559   5.03   244.9   $0.02
-0.020559   5.03   244.9   $0.02
-0.020559   5.03   244.9   $0.02
-0.020559   5.03   244.9   $0.02
-0.017764   4.35   244.9   $0.02


In this case I paid $0.10 of fees instead of $0.07 (0.25%).
any other explanation than what mmitech suggested earlier in this thread ?

Does it make any difference on how orders get split if one places an instant or limit order ? I think I read in this thread it doesn't, so there's no other way than keeping your fingers crossed that an order won't be split too often to keep the fees down ?

thanks for any hints
netpeak

What an unprofessional exchange, it turns out. Money greedy bastards. Rounding for your favour is a criminal act. Book keepers have went to jail for that in the past. Although I have a verified account in Bitstamp, I hope to never use their services again. Asking dumb questions about my money was one thing, but stealing in the given way destroys all trust I had for them.

Just for the record you retarded forumites, I had a discussion with Nejc about this problem in 2012 (was said to be worked on).

I put out a warning even on this forum in 2013 but noone gives a shit. (You can look it up, history if now banned username 'kakobrekla')

You deserve even worse tbh. Delete your wallets, at least you wont make the scammers richer.

And as for the new fee structure, it is still possible for their trading engine to take 1 satoshi from your order and charge you 0.01 usd for it. Calc the fee amount on this one.

Enjoy.

Oh yeah, side story, I also K-Lined Nejc from freenode in 2012 because of spamming. Such ethics.

wow that is incredibly dishonest and you know as well as i do, anyone going over logs would have seen that and been, to a buddy of course, "man you wont believe this but ive figured out a way to more fee's".

meh

Exactly. You can never reach 0.5% fee when the rounding is always UP.

i actually don't think a 5$ minimum fixes the rounding issue.
strictly speaking: only having orders that are multiples 5$ would fix it.

i think Bitstamp needs to consider adding more decimal places, as has been suggested

Yeah, you're right, completely forgot about this. It can totally be gamed, just sell your coins in small chunks to avoid the fee altogether, guess we're back at "the correct answer is to count properly with higher precision"

Theoretically, even counting at an arbitrarily large, but finite, precision can be gamed this way. Even with 8 digits of precision, buying satoshis one by one at a 100 Currency/BTC spot and a .5% commission rate would lead to 5E-11 BTC fees being rounded to 0 (given a 1E-8 precision).

Even with a minimum trade amount you'd have some small rounding artefacts on fees due to small partially filled order remainders being executed against, so you have to take an extra step.

So, to summarize, the most correct course of action is to
 - Count with an arbitrary precision, preferably very small,
 - Impose a minimum order size that is a very large multiple of the precision
 - Remove bids from the book when their remaining volume is smaller than (precision /(2*fee))
 - Remove asks from the book when their remaining volume is smaller than (execution_price * precision / (2 * fee))

Numerical example for the bid side
 - Spot is 500 USD/BTC
 - Precision is 10^-8
 - Fee : .5% (0.005)



(The reasoning is similar for asks but I can't be fucked right now)

Who knew so much fun could come from working with finite-precision numbers

sure, that is the case of the OP, and now 5$ minimum will limit this problem, unless a retarded person set his bot to execute orders of $5.01 to pay more fees !!! except if the subject here is not only the fees but it is an accusation to Bitstamp of trading against people's orders to make more money from the fees, is this what you want to say ?

It may be retarded but the problem is you don't have to be the one doing it. You can put in one big order and bots can trade against your order in a 100 (or 1000) little pieces, costing you up to an extra 0.01 in fees each time. This may add up to a lot.

I am aware of bots and the way they work but 100 trade a minute !!! why ? it is not like you see major price moves over the course of a minute...it is just plain retard to do that then complain about paying more fees, and again, rounding prices up is all around your daily life, you just don't feel it or know about it.

if I had an exchange I would stick to the $0.01 as well, there is nothing less then a penny so complaining about it is just plain stupid, the only thing that could work is taking fees in Bitcoin but I don't see how you can work this out, because at some point you have to sell the coins and I also don't know how can this be reported for taxes...   

This is wrong because there is automated trading that does a high volume of trades in a short period of time. Even if you don't do this yourself, if your orders are traded against by algorithms you may get many, many executions. There is no reason to assume 100 trades in a month is a lot. You could get 100 trades in a minute.

I think this could likely be gamed unless rounding were done randomly (and then it is difficult to audit) and it would not average out.

Either this, or round fairly, because on average it would even out.



+1, it's not like it wasn't clearly laid out.

Mischarged is going to far. It was according to their posted (but dumb) policy.

They can certainly refund if they want to do that as a customer relations move, but I don't see any mischarging here.

I never had a gas station round UP on me... Damn right i would complain, it's just not fair.

Adding more decimals is the only fair solution for both parties.

Still waiting for the Fix ! Bots having fun meanwhile 

Time             Price         Volume      USD           
21:00:17   452.58000   0.0022   1.0100
21:00:17   452.59000   0.0022   1.0100
21:00:17   452.60000   0.0022   1.0100
21:00:16   452.61000   0.2972   134.5055
21:00:07   452.61000   0.0022   0.9981
21:00:05   452.61000   0.0022   0.9981
21:00:05   452.61000   0.0022   0.9981
21:00:00   453.47000   0.0022   1.0100
21:00:00   453.48000   0.0022   1.0100
20:59:51   453.49000   0.0022   1.0100
20:59:35   453.50000   0.0022   1.0000
20:59:32   453.50000   0.0022   1.0000
20:59:31   453.50000   0.0022   0.9999
20:59:28   451.51000   0.5533   249.8211
20:59:23   453.50000   0.5060   229.4500
20:59:22   453.50000   0.0022   0.9999
20:59:18   451.51000   0.4508   203.5385
20:59:16   451.76000   0.2570   116.1023
20:59:13   453.51000   0.0022   1.0100
20:59:13   453.52000   0.0022   1.0100
20:59:12   453.53000   0.0022   1.0000
20:59:07   453.53000   0.0022   1.0000

So is BitStamp going to refund the excess fees they mischarged customers?

congrats, you just lost me here, and welcome to my ignore list.....another fact, bitstamp still makes millions when you are crying as a baby here, this didnt change for sure, see my limited retarded brain still understand that