I've been a reading fiend lately, particularly when it comes to darker YA fiction that's been published in the last five or six years. Each book has its distinct qualities and unique flares, but I've also noticed some patterns emerge. It's important to talk about this because if you're a writer serious about publishing, you must know what's popular on the market so you can both stand out and fit in. It's a delicate balance I haven't quite figured out myself. Regardless, let's look at some trends.
Female protagonists
If you've read more than one YA book or have at least perused the blurb on the back of the book, you probably will have noticed that most books feature not only a female protagonist but a female-centric cast of characters, which I'll talk about later.
Angry protagonists
Not only are these protagonists mostly female, but they have anger problems that lead to destructive thought patterns, obsessions, and actions. I can't speak for all the genre categories, but this seems to be the case for at least darker YA books with elements of horror or fantasy. They often end up getting the revenge they're seeking by the end. Isn't that interesting? Screw positive character arcs.
Single parents
Not only are single parents a trend in YA, but I'd go as far as saying they're a staple of YA fiction--something I noticed as I read YA in high school. With some exceptions (such as The Cemetary Boys and Clown in a Cornfield), the single parent is usually the mother. The deadbeat parent is either dead, abusive, crazy, or negligent, and the parent who's still around is depressed, an alcoholic, secretive, or too absorbed in their own problems to notice that their kids are going off the deep end. It's also popular for the protagonist to not even know who her dad is.
A dramatic move to a creepy place after a death
This one seems oddly specific now that I've written it out, but I kid you not. I can think of five books off the top of my head where this happens. Someone dies, either a parent or a grandparent, and the protagonist and her single-parent must move into a remote town with close-minded Republicans because they're broke with nowhere else to go. Oh, and the house and/or town is haunted.
There's also a sketchy backstory about the person who died, which is always tied to the spooky supernatural stuff happening at the present time. It's always some sort of secret the single parent is keeping from his/her daughter.
Mother-daughter relationships
With all these female protagonists and their usually single mothers, this gives authors plenty of time to explore a mother-daughter relationship on the page. The mother's usually got her issues and her secrets, and the relationship with her daughter might be strained at some points during the novel, but she often pulls through at the end by showing her love for her daughter in some real way.
Sister-sister relationships/female friendship
See what I mean when I say YA is very much into girl power? I've read so many sister books lately. If the girls aren't actually sisters, they're at least best friends who are so close, they're practically sisters. They're not maniacal or vengeful or constantly trying to tear each other down. In fact, it's quite the opposite. They may have their arguments or moments of weakness, but overall, they're on the same team. They're strong, independent, angry women who band together against the forces of evil.
Men are bad
Those forces of evil are often men. Men who abuse their power, neglect their daughters, abandon their wives, harm their girlfriends, or treat women like objects. The few good men in YA are either dead or on the peripheral of the story. There are a couple of good dads out there, but not many.
Little to no romance
Now, this is a trend I can get behind. Several of the books I've read lately might touch on one character feeling attracted to another, but it's often a subplot that has little bearing on the story. This little flare-up of attraction usually doesn't amount to anything by the end. On another note, I can't remember the last time I read a book with a love triangle. It's safe to say that everyone is sick of those (except me, apparently).
Seventeen
Most of the characters I've been reading about lately are seventeen and seniors in high school (with maybe an occasional sixteen-year-old junior). It was refreshing to read about a fifteen-year-old freshman in Some Kind of Animal, but other than that, YA skews older, probably because it allows authors to explore heavier or darker themes. In my experience, writing upper YA is easier. The younger your characters, the harder it is to remember what it was like. By sixteen or seventeen, puberty is pretty much over, and our hormones have leveled out a bit (kind of). Upper YA probably has a wider audience, too. Kids from middle school and on will read it, whereas older teens might not want to read about a fourteen-year-old.
What now?
By now, you're probably wondering, so, should I write to these trends because everyone's doing it, or should I write away from these trends because everyone's doing it? The truth is, I have no idea. I'm not an industry professional. It almost seems like the best thing to do is study the market, figure out where your book fits into that market, and write according to where you think these current trends will lead. You're doing a little forecasting and keeping your fingers crossed that you're right, and that you'll hit the market at the right time.