I've done my daily skim through the markets and there are a lot of weak low-volume markets later on this afternoon, so I'll be shutting down the computer and getting ready for the pub early today!
At the time of writing, the highest traded markets on betfair are at 2:45 and 4:45 with £77k and £80k respectively. Contrast with the fact there are no races from the 4:50 (£5k) until evening racing that have more than £10k traded, except the 5:25 (£12k). Some of this is probably due to the earlier races in the day attracting slightly more attention early in the day, but not that much.
Obviously this makes these weaker markets different to trade - more risky and probably more jumpy. Personally I really like the jumpy volatile markets but it does become more like gambling so I steer clear of the really weak ones. It is much much easier to have a large loss because if the market turns sharply, there will be a lot of traders desperately chasing the same limited money to get out of their trades.
These weaker markets tend to be later in the day (and the Irish courses), so don't kick yourself when you always seem to cock-up your P&L and strike rate for the day - maybe just consider avoiding these races.
Whilst the 5:25 might have enough volume when it comes to trading time and actually represent a good opportunity, I think I'll be knocking it on the head for the day after the 4:40 as waiting 45 minutes for one more race to trade isn't much fun! All the best for today.