Erroneous after hours stock pricing - why?

artyboy

Ok so this has been bugging me for a while, and I'm hoping someone can shed some light. I've noticed that quite often, stock prices after 4:30pm (specifically LSE listings here) can sometimes spike or tank significantly. I know there is an auction period after the main market closes, but these movements seem to correct themselves back to the close price next day.

A particularly extreme example today is HSBA - it closed slightly up but appears to have dropped over 5% since.

is this just bad data or is there a genuine reason for why this gets displayed, and then reversed next day?

Mark_d

Looks like dodgy data.   What does the picture look like for LSE:HSBA when you look at different information sources, YouInvest, MSN Money  etc.

wmb194

artyboy said:

Ok so this has been bugging me for a while, and I'm hoping someone can shed some light. I've noticed that quite often, stock prices after 4:30pm (specifically LSE listings here) can sometimes spike or tank significantly. I know there is an auction period after the main market closes, but these movements seem to correct themselves back to the close price next day.

A particularly extreme example today is HSBA - it closed slightly up but appears to have dropped over 5% since.

is this just bad data or is there a genuine reason for why this gets displayed, and then reversed next day?

Stop using Google? The LSE's price should always be correct and that's not what it says:

This price is determined by the outcome of the end of day auction (16:35):

https://www.londonstockexchange.com/stock/HSBA/hsbc-holdings-plc/company-page

TradingView is displaying the correct price:

artyboy

dodgy data then... thanks.

Cold_comfort

Google is picking up the last reported after-hours trade which happened to be at a significantly discounted price compared with all other trades.