Topic: [BETA]Bitfinex.com first Bitcoin P2P lending platform for leverage trading - page 41. (Read 137528 times)

How high is this "reasonable" number? Depending on the time frame you look at, BTCUSD goes up in annual numbers I would deem "unreasonable".

Maybe you could just calculate VIR like this:

For every atomic time unit (seconds?) calculate the following number:
Total amount of interest paid on loans (either USD or BTC) / Total amount of USD/BTC currently in active loans

Then either take the arithmethic mean or (if you're really worried about outliers) the median value of these and call it the average interest of the hour/day/week...
Lenders then can choose to either lend out at the average value of the last X hours/days/weeks or enter their own offers into the engine.

This makes sure 1 USD lent out at a few million% doesn't change interest rates that much. I still wonder if you really do a weighted average (over a few days!) how VIR can still vary that much even over 1 day. My suspicion is still that VIR itself is not factored in, only fixed rate loans (of which there might be fewer).


In general about lending:
* Grouping offers/demands makes 0 sense, if you then can't fill 'em! I click the check box next to a loan demand, some numbers get pre-filled and still have NO idea how high the real demand was, as I can't trust the interest rate displayed at all. Also even though I tried to use all information available to me, I still have to guess numbers, as "10%" means "0.0001%-10.0000%". I have no clear way to fill loan demand at the moment. Imagine placing offers with ONLY the MarketDepth chart on http://bitcoincharts.com/markets/mtgoxUSD.html available...

* It is hard to have this additional 3rd measurement (offer time) next to amount and APR. Maybe instead of clustering by APR, you could cluster by time? (Offers between 1-10 days, 11-31, 32-61, 62+)

* To also get a few trades on your platform going you might offer the setting that interest received from lending out BTC/USD gets automatically converted to the other currency (or only BTC/USD) via an automatic market trade on either the internal or MtGox market, whatever yields more (e.g. on internal I get 0.5 BTC after fees for my 40 USD, on MtGox 0.52 --> trade on MtGox). You might even offer a split (keep 10% of interest in USD to fight fiat inflation, convert rest to BTC because you're "cowardly long" on BTC )

* Please display offers as they were entered somewhere - it might be fine to display a grouping for overview (graphics might be even better...) but there should be some kind of advanced page where you can find exact numbers (maybe with some filters?) to post/fill offers.

* Please display the current (I think it's valid for 15 minutes, right?) APR next to "V.I.R." in brackets, something like "V.I.R. (currently 234.5678%)".

Also giving a few numbers on how much profit your traders + lenders make might be interesting and be good PR (as far as I've seen, most users should have profited quite a bit from the recent rally, even through some growing pains and MtGox lags!).

All in all thanks for addressing issues quite quickly so far and constantly communicating/looking for suggestions/solutions! This still is beta and especially the current issues in lending are probably also just display issues that need to be figured out (show each single offer of a few cents vs. when to group while still making sure offers can be actually filled and not spamming the page).

a proposal for an improved VIR calculation.

Why are we trying to squeeze all into one factor? My observation is that actually we try to achieve two different things

• we want the VIR rates to reflect the integrated market situation. When demand is high, VIR should go up.
• we want to protect ourselves against excessive VIR rates.

Thus the idea is to create the actual VIR out of two factors, which correspond to these goals.
The protective factor could be choosen as a function, which is "hard" at the borders and "soft" in the center. I have a variation of a bell function exp(-k*x*x) in mind. That is, we have kind of a standard derivation; maybe we apply this in a way that VIR is at a "medium value" and can will remain within e.g. 3 times that value or 1/3 of that value with more than 99% probability. This way, that protective factor would create a channel. Within that channel, we apply the market demand factor, which reacts more quickly to the current market situation.

For example, the protective factor...


...so we could use such an 1 month moving average, which weights each contribution both by the size and the duration it was actually taken. This would give us a quite rigid channel.

Within that channel we could use another, shorter time-base  average, which reacts way more sensible to the current market situation.

(as a plus, the protective factor, which is more expensive to calculate, could be updated with a slower rate, e.g. 4 times a day)


Thus, when the market behaves like this night, we would get a channel centered at the long term average, say 250% APY, but the current high demand would drive that temporarily up to maximally -- say -- 3* 250%

Hi,

You can already activate Authenticator security here: https://www.bitfinex.com/account/security

And I strongly advise anyone to do that. When I have doubt about withdrawals I send email to the user, but it may not always be the case in the future, as we are getting more and more withdrawals each day.

About the VIR:

I have change the VIR calculation: you can still chose to borrow and lend at Xmillions% a year if you feel like it, but the VIR calculation will ignore loans that are above a certain (reasonnably high) rate. This will allow the VIR to stay within some ranges from day to day and prevent it to jump and empty your balances. This is still a free market rate, but it should make it immune to manipulation.

Let me know if you have any questions
Best regards
Raphael
Bitfinex team

Hello,

Just reading

http://www.reddit.com/r/Bitcoin/comments/1b12mz/public_service_announcement_turn_on_mtgox_double/

I was wondering if supporting Authenticator is a feature also planned to offer for bitfinex?

Thanks!

 Hello everyone,

 I'm on my phone so message will be short. I agree that  VIR can not  spike like that and  out ask traders margin at risk.  We thought problem was addressed but it's still not immune to manipulation.  We ll correct that.  we're will also compensate for traders that lose a lot because of the spike.  contact me  at  [email protected]  to signal you are concerned, but understand that  it will take me some time to deal with this issue and crawl  back history.

 also,  the community forum is temporary down, it did not stood the charge.  give us some time to put it  back up.

 Brett regards
 Raphael

example

I like that idea. However, it would mean that VIR would adjust more slowly to market changes. Maybe the 30 day period could be shortened in turn to compensate at least in part for that?

Unless someone comes up with a downside to this approach, I'd be all for it.

I don't quite like the (partial) profit share idea. It just adds unecessary complexity and it's not what a lender typically wants (correct me if I'm wrong).

does the VIR calculation not take into account volume (sum(volume*rate) / sum(volume) or something)? How large was the loan taken at the insane rate?

How long has the interest earned fee been 10%?

cancel the offer and post them again .... i dont have any other idea :S

i am off drinking and trading is not a good combo

have a nice bitday

Another suggestion. Can we have an option on the lending page to disable all grouping and rounding. Right now I see:
Minimum lending time (days)   Rate (% per 365 days) *   Amount   Demand count   
60    310.0%    7582.81   4

I am curious to see the lending time of each of those 4 offers.

Fully agreed.
I think just we need to fine tune that formula, so that no one can poison the VIR rates.

Right now VIR is between 300% and 400%, which is fully adequate to the current market situation. But a sudden spike to 400000 % is never adequate, and IMHO we should find a way to prevent that from happening.

That one auto-renewed but the other ones just went to my lendable balance.

it was put together whit a 60 days offer

returning the loan now

Yes it was taken, strange as it didn't show in the list.

taken
can you confirm is was taken ?

It shows unfilled for me, but doesn't show in the list.  500 days the issue?


Unfilled credit demand/offers
#    Currency    Type    Amount    Rate (% per 365 days) *    Maximum lending time (days)    Placed    Auto-renew    Status    
22308    USD    Lend Limit    223.92    728.0%    365    2 minutes ago    Yes    active    Cancel   Will notify
22304    USD    Lend Limit    1.0    1000.0%    500    6 minutes ago    Yes    active    Cancel   Will notify

check the
i dont think u posted the offer correctly

Done

you have to set the auto renew when you post the offer

is working since the 10000010.0% offer is back on the lending page

can you make a test plz ? put 1 USD at 1000% APY for 500 days i take it and pay back the loan to see if get reposted