Why CMC markets data differ from other sources?

Does anyone else use CMC markets as their CFD broker? I found their data (eg. close, open, high, low etc) are slightly different from Norgate Data and other sources like Market Index (see link below) , Norgate and Market Index are the same though. I am wondering why and what the solution could be. (I use the Australian Stock Predictive Discovery as an example)

Predictive Discovery Ltd (ASX:PDI) Share Price - Market Index

Thank you

CFDs are correlated to the underlying instruments.

However, you need to understand that the CFD broker won't necessarily match the underlying instrument's trading.

Differences may related to a "haircut" that the CFD provider takes to provide you the CFD instrument. For less liquid instruments, it might also related to alternative tradng venues (eg Cboe Australia) trading prices.

Could you provide an exact recent example? i.e. exact time (at least within a minute), what you saw and what you expected?

Thank you for your reply. Could you explain "hair cut"?

I do EOD, I attach here screenshots of the same stock Predictive Discovery (PDI) from Norgate, Market Index and CMC.

On Mar 1 2024
Norgate: O 0.19, H 0.195, L 0.185, C 0.19
Market Index: O 0.19, H 0.195, L 0.185, C 0.19
CMC: O 0.185, H 0.19, L 0.185, C 0.188

So CMC is different, I am wondering why.

A CFD is a derivative instrument.

CFD brokers are not obligated to following the underlying instrument's pricing - they have effectively created their own instrument.

Norgate Data reports exchange-traded prices according to the exchange's rules of how to report OHLCV data points.

I can't comment on what CMC are showing on their charts - but it's clearly different.