Author Topic: Price Feed Review  (Read 7082 times)

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Offline clockwork

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Re: Price Feed Review
« Reply #15 on: May 09, 2019, 06:59:41 pm »
only got round to accessing my feed script today just now.

My feed was actually the highest just now without changing anything a few hours later...I know we all wish BTS never moved down but guess what...it does....are we gonna have this discussion and people calling hard-working witnesses names EVERY time BTS moves down? Let me know so I can be prepared. It's crypto...it's volatile...it goes up and and it goes down. I don't like it either but it happens.

Still... I disabled the outlier CoinEgg component of the feed as it seems untrustworthy. Feed now 4% above median

Offline alt

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Re: Price Feed Review
« Reply #16 on: May 09, 2019, 09:30:14 pm »
I can't imagine what logic can be used to implement disapprove witness automaticly based on the feed price.
it's unresponsoble to vote witness automaticly by proxy, if somebody did this, please let me know.
BTW, did this development pay by worker income?

While we are at it, I started working on a python project that is supposed to automatically disapprove (unvote) witnesses that provide inaccurate feeds (relative to price feed) here:

https://github.com/xeroc/witness-monitor

Any development resources to improve that would be welcome.

Offline sahkan

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Re: Price Feed Review
« Reply #17 on: May 09, 2019, 09:39:32 pm »
Time: UTC 9th May 12:15





Warning:delegate-1.lafona, sahkan-bitshares, witness-hiblockchain, zapata42-witness, xeldal at the time feed a 2%+ lower price than reasonable.

Again, our feeds are not every second. It's a price snap shot taken within some specific period 20-40 minutes (2 in your case) so it's an unreasonable statement based on some snapshot in time. price feeds should average out to a true price among all witnesses. Look at the screen shots later on, my price happen to be 2% above on the other side of that price medium is that a warning also?

And when will GDEX start feeding all prices? Should be unvoted  by proxies until it does.

Offline binggo

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Re: Price Feed Review
« Reply #18 on: May 10, 2019, 12:26:43 am »

Again, our feeds are not every second. It's a price snap shot taken within some specific period 20-40 minutes (2 in your case)

The feed price should provid within 5 minutes, within 3 minutes more better.

The pirce from specific period 20-40 minutes is a fake price.

BTS is a DEX, not MakerDao.

Offline zhouxiaobao

Re: Price Feed Review
« Reply #19 on: May 10, 2019, 05:10:56 am »
Most of the trading volume in the CEX is fake, and the trading volume in the DEX is already more than the actual trading volume in many CEX.The actual price of the DEX  should be taken into account in the feed price.

Offline xeroc

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Re: Price Feed Review
« Reply #20 on: May 10, 2019, 07:40:26 am »
Of course you need to have reasonable configuration. But surely, if a single witness publishes a feed that is 5% (or more) away from feed price, the proxy should at least be notified.

Unvoting a witnesses can be justified when the last feed was older than 2 days, or when he doesn't follow consensus when it comes to MSSR or MCR.

I wrote this code in my spare time, as usual ..
I can't imagine what logic can be used to implement disapprove witness automaticly based on the feed price.
it's unresponsoble to vote witness automaticly by proxy, if somebody did this, please let me know.
BTW, did this development pay by worker income?

While we are at it, I started working on a python project that is supposed to automatically disapprove (unvote) witnesses that provide inaccurate feeds (relative to price feed) here:

https://github.com/xeroc/witness-monitor

Any development resources to improve that would be welcome.
Give BitShares a try! Use the http://testnet.bitshares.eu provided by http://bitshares.eu powered by ChainSquad GmbH

Offline bitcrab

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Re: Price Feed Review
« Reply #21 on: May 10, 2019, 07:47:51 am »
only got round to accessing my feed script today just now.

My feed was actually the highest just now without changing anything a few hours later...I know we all wish BTS never moved down but guess what...it does....are we gonna have this discussion and people calling hard-working witnesses names EVERY time BTS moves down? Let me know so I can be prepared. It's crypto...it's volatile...it goes up and and it goes down. I don't like it either but it happens.

Still... I disabled the outlier CoinEgg component of the feed as it seems untrustworthy. Feed now 4% above median

I don't think the higher feed price, the better, feed price should reflect the real market price. as feed price will have direct impact some operation, such as margin call, borrowing, force settlement.

it is not easy to judge what is "real market", but at least we can have some principles:

first, it is to get DEX price plus with smartcoin premium/discount as a reference, this is the most important reference.

second, it's not good to get average price of too long period and feed, an average of 5 min should be fine.

Offline bitcrab

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Re: Price Feed Review
« Reply #22 on: May 10, 2019, 07:58:09 am »
Again, our feeds are not every second. It's a price snap shot taken within some specific period 20-40 minutes (2 in your case) so it's an unreasonable statement based on some snapshot in time. price feeds should average out to a true price among all witnesses. Look at the screen shots later on, my price happen to be 2% above on the other side of that price medium is that a warning also?
And when will GDEX start feeding all prices? Should be unvoted  by proxies until it does.

feed price should reflect the real market price, 20-40 minutes as price taking period is not acceptable.

"the higher, the better" is not my opinion. but now the main problem of feed price is some witnesses always feed too low price. we need to focus on this.

it's not difficult for me to request my coder to add feed price to all the smartcoins, but I am not sure that will make big sense.

taking bitEUR as one example, it has a supply of 57000 EUR and 24hour volume is about 4000 BTS, there are many users and important community members that come from Europe, but anyone care bitEUR?

if we really want to cultivate bitEUR, we need to consider to change something, such as MSSR, MCR, market fee etc., but seems no one want to do that.


Online bitProfessor

Re: Price Feed Review
« Reply #23 on: May 10, 2019, 10:08:54 am »
Of course you need to have reasonable configuration. But surely, if a single witness publishes a feed that is 5% (or more) away from feed price, the proxy should at least be notified.

Unvoting a witnesses can be justified when the last feed was older than 2 days, or when he doesn't follow consensus when it comes to MSSR or MCR.

I wrote this code in my spare time, as usual ..
I can't imagine what logic can be used to implement disapprove witness automaticly based on the feed price.
it's unresponsoble to vote witness automaticly by proxy, if somebody did this, please let me know.
BTW, did this development pay by worker income?

While we are at it, I started working on a python project that is supposed to automatically disapprove (unvote) witnesses that provide inaccurate feeds (relative to price feed) here:

https://github.com/xeroc/witness-monitor

Any development resources to improve that would be welcome.
Great!

Offline sahkan

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Re: Price Feed Review
« Reply #24 on: May 10, 2019, 09:49:43 pm »
Again, our feeds are not every second. It's a price snap shot taken within some specific period 20-40 minutes (2 in your case) so it's an unreasonable statement based on some snapshot in time. price feeds should average out to a true price among all witnesses. Look at the screen shots later on, my price happen to be 2% above on the other side of that price medium is that a warning also?
And when will GDEX start feeding all prices? Should be unvoted  by proxies until it does.

feed price should reflect the real market price, 20-40 minutes as price taking period is not acceptable.

"the higher, the better" is not my opinion. but now the main problem of feed price is some witnesses always feed too low price. we need to focus on this.

it's not difficult for me to request my coder to add feed price to all the smartcoins, but I am not sure that will make big sense.

taking bitEUR as one example, it has a supply of 57000 EUR and 24hour volume is about 4000 BTS, there are many users and important community members that come from Europe, but anyone care bitEUR?

if we really want to cultivate bitEUR, we need to consider to change something, such as MSSR, MCR, market fee etc., but seems no one want to do that.

People that have bitEUR care, and RUBLE is another rapidly growing market as RUDEX is becoming more popular.

Offline abit

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Re: Price Feed Review
« Reply #25 on: May 10, 2019, 10:18:52 pm »
Again, our feeds are not every second. It's a price snap shot taken within some specific period 20-40 minutes (2 in your case) so it's an unreasonable statement based on some snapshot in time. price feeds should average out to a true price among all witnesses. Look at the screen shots later on, my price happen to be 2% above on the other side of that price medium is that a warning also?
And when will GDEX start feeding all prices? Should be unvoted  by proxies until it does.

feed price should reflect the real market price, 20-40 minutes as price taking period is not acceptable.

Things to remember:

1. if price change is within a threshold (E.G. 0.1%, of course need to be small enough), to avoid chain bloat, it's better to skip feeding a new price. So it's possible that no new feed got published for a relatively long period, the reason is too little change in price. IMHO an average interval of 5~20 minute is good enough.

2. there were people crying in the past that "it's easy to dump in CEX to trigger margin calls in DEX". Come on, please put thick enough buy orders with your own money in CEX to prevent the price from dropping.

3. DEX price * premium? How to know how much the premium is? Volumes of the fiat gateways (MagicWallet/bitCNY:QC in ZB/bitCNY:CNC in AEX) are so low recently, which can not justify the premium. Also the gateway price (aka deposit/withdrawal processing fee) can change quickly.

4. volumes on many CEXs are FAKE.

By the way, we have some charts here: http://pricefeed-tracker.dex.trading/
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Offline binggo

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Re: Price Feed Review
« Reply #26 on: May 11, 2019, 12:41:19 am »
Quote

2. there were people crying in the past that "it's easy to dump in CEX to trigger margin calls in DEX". Come on, please put thick enough buy orders with your own money in CEX to prevent the price from dropping.
I don't think this focus on the topic and a good talking.

You can you up?

Is it not a truth? or the design of feed price is perfect and not allowed people to judge it?


Offline zhouxiaobao

Re: Price Feed Review
« Reply #27 on: May 11, 2019, 01:18:13 pm »

Things to remember:

1. if price change is within a threshold (E.G. 0.1%, of course need to be small enough), to avoid chain bloat, it's better to skip feeding a new price. So it's possible that no new feed got published for a relatively long period, the reason is too little change in price. IMHO an average interval of 5~20 minute is good enough.

2. there were people crying in the past that "it's easy to dump in CEX to trigger margin calls in DEX". Come on, please put thick enough buy orders with your own money in CEX to prevent the price from dropping.

3. DEX price * premium? How to know how much the premium is? Volumes of the fiat gateways (MagicWallet/bitCNY:QC in ZB/bitCNY:CNC in AEX) are so low recently, which can not justify the premium. Also the gateway price (aka deposit/withdrawal processing fee) can change quickly.

4. volumes on many CEXs are FAKE.

By the way, we have some charts here: http://pricefeed-tracker.dex.trading/

     
     1、 There is a gap between the prices of BTS in various exchanges. Why is there no arbitrage?Because there are all kinds of handling fees.However, you witnesses did not consider handling fees for all kinds of conversion of BTS prices.
      BTC--->BTS---->USDT----->CNY......   
      These price conversions do not take into account handling fees, so the feed price is always lower than the actual price.
      The highest price of BTS in major exchanges (including the DEX) is closest to the actual price.

      2、 Why can't the DEX price be taken into account in the feeding price? The volume of DEX has already exceeded tens of millions, surpassing many CEXs.
     Is it because the price is difficult to determine?
     How much does it cost for us to buy a BTS in the DEX? This is very clear,DEX price *Recharge rate.
     This is the real price of BTS, at least the feed price cannot deviate too much from this price.
     Why has MSSR dropped to 102%, and BITCNY premium is still large? The important reason is that the feed price is lower than the actual price.

Offline abit

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Re: Price Feed Review
« Reply #28 on: May 11, 2019, 01:34:59 pm »
Quote

2. there were people crying in the past that "it's easy to dump in CEX to trigger margin calls in DEX". Come on, please put thick enough buy orders with your own money in CEX to prevent the price from dropping.
I don't think this focus on the topic and a good talking.

You can you up?

Is it not a truth? or the design of feed price is perfect and not allowed people to judge it?
People complained that witnesses updated price feed too fast when there is a dump happened on CEX. Now same people complain that witnesses updated price feed too slow when there is a pump? WTF?

Both longs and shorts are traders, we should treat them equally. That said, feed fair price, not too high, not too low. Don't change interval in downtrend nor in uptrend.
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Offline zhouxiaobao

Re: Price Feed Review
« Reply #29 on: May 11, 2019, 02:06:02 pm »

if DEX's price*premium>1.05*CEX's price 
   feed price = 1.05*CEX'price
otherwise                     
   feed price = max(DEX's price*premium,CEX's price  )

premium=(Recharge rate+Withdrawal rate)/2