I don't understand this, with this moment the A´s down 2.44% and the B´s 2.40%?

The A shares suffer from low trading effects. I just got a quote from Yahoo showing the A shares down 2.5% at 693,734.6. This is despite both Bid and Ask behind higher than this (693,841.5 and 694,420 respectively). Basically the quote for A lags until a sale gets made, while the B quote is more realtime.

A quick look at A vs B trading can give you either deceptively high A/B or deceptively low A/B ratio depending on where A's are in the lagging. I believe the discrepancy remains at close, with A-shares showing the last-price regardless of what the Bid and Ask prices were.

My point was just that higher A/B ratios can be explained by increased demand from a large purchaser (maybe Buffett), or reduced supply by lots of sellers that don't follow the day to day market. I didn't really look closely at what we're trading at today.