Comparing the price feeds of two brokers on the same pair, what the differences were
I had accounts with two brokers and ran charts for the same pair side by side for a few weeks. I wanted to see how different the prices were, because I'd heard that feeds vary.
Most of the time, the prices were close, within a fraction of a pip. The differences showed up at specific moments: the opens of sessions, around news releases and near rollover. At those times one feed would spike a little more than the other, or the spread would be wider on one. Highs and lows of candles differed by a pip or two on some bars, which matters if you're trading from the high and low of a range.
That had some practical effects. A level I marked on one chart might be a pip off on the other. A stop that was safe on one feed could have been touched on the other. So I realised I should test my strategy on the feed I trade, not on a different one.
It also taught me not to compare my trades with a friend's on another broker and expect the same result. Small differences exist, and they accumulate.
Comparing the price feeds of two brokers on the same pair, what the differences were
Re: Comparing the price feeds of two brokers on the same pair, what the differences were
This matches what I saw too. The candle highs and lows were the biggest difference, which matters a lot if you trade the Asian range or anything based on exact extremes. One feed had a spike to a high that the other never printed. If I had been using the second feed to mark levels, the range would have looked different and the breakout would have triggered at another price. Now I mark my levels only on the broker I trade with, and I treat anything from another chart as a rough guide.
It’s Fairman 
Re: Comparing the price feeds of two brokers on the same pair, what the differences were
Worth adding that a lot of people mark levels on TradingView and then trade on a different platform. The data source on TradingView may not be your broker at all, so the levels can be a pip or two off from what you are actually trading. For a swing trader that is nothing, but for a scalper with a small stop it can be the difference between being stopped and not. I either use my broker's feed on TradingView if it is available, or I mark the final levels on the trading platform itself.
It’s Fairman 