Dear Madam, Sir,

By a relatively high margin, the historial Yahoo Quote opening price
(CSI data)is often not identical to where the intraday chart (Reuters
quote ??) started.

What I read for SPOT on Monday, October 13 (and what I obtained from
InteractiveBrokers tick data) ist close to 15.73, the historical
opening value reads 15.87.

I would be very interested to know if there is any regularity
(sometimes a value of 15min after the opening bell comes close, but
then not).

Therefore I would like to ask if any weighting or filtering of
volume/bid/ask/last values is used for the determination of the
historical opening value.

I direct inquiry at CSIdata yielded simply "the opening price is the
first trade".

Your answer should provide a deeper order, if any.

Thanks,

Bardo