what is the source for price feeds and settlement price?

[pc]

Ok but let's assumo for example that they collude to set the price of the USD 2x higher for tomorrow at 11:00.
At 10.59 they could buy a lot of bitUSD and then then ask for settlement at 11:01 so as soon as they get caught the damage is already done.
Or there is some kind of built in protection?

There is the 24 hour settlement delay. But that doesn't really prevent the scenario above.
Colluding witnesses *can* do damage. But they can't do it anonymously, so they can and will be held responsible for it afterwards.

[jsidhu]

Ok but let's assumo for example that they collude to set the price of the USD 2x higher for tomorrow at 11:00.
At 10.59 they could buy a lot of bitUSD and then then ask for settlement at 11:01 so as soon as they get caught the damage is already done.
Or there is some kind of built in protection?

I believe there is a limit of 10% movement above or below the peg price

[nero.franco]

Ok but let's assumo for example that they collude to set the price of the USD 2x higher for tomorrow at 11:00.
At 10.59 they could buy a lot of bitUSD and then then ask for settlement at 11:01 so as soon as they get caught the damage is already done.
Or there is some kind of built in protection?

[pc]

1) It is the responsibility of each individual witness to provide an "accurate" price, whatever that means. So there is no well-defined source for price feeds. In practice, though, most witnesses use either xeroc's or wackou's price feed script I believe. See https://github.com/xeroc/python-graphenelib/blob/master/scripts/pricefeeds/feedsources.py for examle.

2) Witnesses could collude to manipulate the feed. However, doing so is very very obvious. Each published price feed value carries the signature of its publisher. Shareholders should monitor the published feeds, and in case some fishy behaviour is observed, raise alarms and vote out the misbehaving witness.

[nero.franco]

Hi all!
I have been doing some research but i couldn't manage to understand:
1) what are the sources for price feeds to calculate settlement price in smart coins?
2) if the prices are fetched and fed to the network by witnesses ...then who assures that witnesses don't collude to manipulate the price feed at their coinvenience?
   i have see that the number of witnesses is really small, it would be quite easy for them.

I hope that someone can reply to my questions, thanks.