Nothing is wrong with BritCoin itself, but there must be SOMETHING wrong when it is reporting that a sale was made where somebody paid 10,000 pound for a BitCoin, I am certain that sale never went through or was for a small amount of BitCoins, it shouldn't have even got matched in the first place!
All the erroneous data needs to be cleaned out, when you look at BitCoin Charts and display the last 60 days' activity for BritCoin its all skewered because of this rubbish data!
No, they really happen; I had one myself (not at that crazy rate though).
Their software is buggy; user beware!
Unfortunately if you point out this bug to Britcoin they fob you off.
Their software is buggy and I've offered a fix for it several times now.
The problem is that decisions are made based on how much you are still wanting, rather than the original price you requested.
Genjix has claimed that the 'want' field isn't actually used any more:
You're right, we do ignore the want field. It's mostly left for display and is kind of redundant. It's not even needed.
but I think he's mistaken. The 'want' field is still used, and is exactly what's causing the problem.
Here are some examples that show how very low and very high priced trades happen:
This is how very low priced trades happen:User A has 50 GBP and wants 5 BTC (buying BTC at 10 GBP/BTC)
User B has 6 BTC and wants 54 GBP (selling BTC at 9 GBP/BTC)
User A's order goes in first, and is unmatched.
User B's order goes in 2nd, and is partially matched at User A's rate of 10 GBP/BTC.
User B gives 5 BTC to user A and gets 50 GBP in exchange.
User B now has 1 BTC and
the 'wants' value is updated to 4 GBP.
User C can now come along and buy User B's remaining 1 BTC for 4 GBP, even though the market price is in the range of 9 or 10 GBP/BTC.
Note that overall, User B gets 54 BTC for his 6 BTC, and so actually gets the price he was expecting to. It's just that some was better than expected (5 sold to A for 10 GBP each) and some was much worse than expected (1 sold to C for 4 GBP).
This is how very high priced trades happen:User A has 5 BTC and wants 45 GBP (selling 5 BTC at 9 GBP/BTC)
User B has 51 GBP and wants 5.1 BTC (buying 5.1 BTC at 10 GBP/BTC)
User A's order goes in first, and is unmatched.
User B's order goes in 2nd, and is partially matched at User A's rate of 9 GBP/BTC.
User B gives 45 GBP to user A and gets 5 BTC in exchange.
User B now has 6 GBP and
the 'wants' value is updated to 0.1 BTC.
User C can now come along and sell 0.1 BTC to User B for 6 GBP, at a price of 60 GBP/BTC even though the market price is in the range of 9 or 10 GBP/BTC.
Note that overall, User B gets 5+0.1=5.1 BTC for his 45+6=51 GBP, and so actually gets the price he was expecting to. It's just that some was better than expected (5 bought from A for 9 GBP each) and some was much worse than expected (0.1 bought from C for 60 GBP each).
This is why absurdly priced trades show up in the API - it's because they actually happen.
My patch to fix this and stop the silly priced trades is here:
https://gitorious.org/intersango/intersango/merge_requests/3