I find that as a "counter-trend" day-trader, the worse aspect of these big-trend days, is that I often actually trade worse than on normal days. Of course this especially sucks, because the big-trend days are when I most need to be at the top of my game, as they are so dangerous to my style.
I think I had an epiphany today though. Last night, I had a feeling that a big-trend day was coming on, and so I looked back through my trading journal and noticed that my worse days tend to be the days when I make the smalelst number of trades.
On a normal day, I'll make at least 40 round-trips or so with a good combination of both long and short positions. Then a big-trend day comes along, and I'll make less than a dozen trades...spending most of the day just watching my day-trading position trade against me in one direction.
I remembered what I had noticed last night this afternoon as I was sitting watching my screen, having averaged down into a large loss. I realized I was missing a lot of good scalps, and had hardly traded at all today, because I was waiting for the market to come back in favor of my much larger than normal position. So I started trading back and forth again, after freeing up some capital by closing most of my existing position at a loss, and was able to make back most of the loss by the end of the day...trading on overdrive (I made about as many trades as I do on a typical day, in just the last 2 hours or so.)