Honestly, I have talked to agents that said not to chase a trend because everyone does it and then you are in a pool with the same trend followers.
This reminds me of my grandfather. He was a farmer. He'd plant corn one year and get a good price say it was 5 dollars a bushel. Other farmers would say, 'Hey, look at how well corn did last season! Let's plant some.' Suddenly there was an surplus of corn on the market and because there was an excessive amount, the price would drop to say 2 dollars a bushel--a three dollar difference compared to the previous season and the other farmers lost out. Whereas my grandfather would look at the market and say, 'Hm. Corn did well last season, I'm going to plant wheat." Because he diverted from the trend, he made more per bushel because while he was planting wheat everyone else was planting corn. The lack of wheat on the market upped its price. Supply and demand.
My grandfather always tried to plant the opposite of what was 'trending' and did far better financially. However, one year the price of wheat was so pathetic, he decided instead of selling it for 2 dollars a bushel he'd raise pigs and feed it to them. By time he sold the pigs, he figured that he actually made 6-7 dollars a bushel for the wheat just by feeding it the pigs and selling the pigs off to market later on.
Looking at what's trending in the YA or MG market is a good idea, but in my opinion, it's only good to see what should be done in opposition to the trend.