When you think about Halloween, you probably picture candy, costumes, and maybe a few too many fake cobwebs. But here is something genuinely spooky that most people never notice: Halloween is enormous business. This year, Americans are expected to spend a record of about $13.6 billion getting ready for one single night. That is not a typo. Billion, with a B.

So where does all that money go, and why do we spend so much on one holiday? Welcome to the spooky economics of Halloween.

A $13.6 billion night

Let’s start with that giant number. According to the National Retail Federation, a group that studies how people shop, about 74% of Americans plan to celebrate Halloween this year, and the average person celebrating will spend around $115. Add all those people together and you get a mountain of money, more than $13 billion, which is a brand new record.

To put that in perspective, $13.6 billion is more than some entire countries earn in a year, all spent on costumes, candy, and spooky decorations.

Follow the money

So what exactly are people buying? The spending splits into a few big buckets.

Costumes take the biggest slice, at about $4.4 billion. From superheroes to witches to inflatable dinosaurs, 71% of celebrators plan to buy at least one.

Decorations are close behind at about $4.3 billion. Those giant skeletons and glowing pumpkins on your neighbors’ lawns add up fast.

Candy comes in at about $4.1 billion, and here is the wild part: 96% of shoppers plan to buy some. That is almost everybody. Candy is the one thing nearly no one skips.

Greeting cards make up the smallest piece, around $800 million.

The strangest number of all

Ready for the spookiest statistic? Americans are expected to spend about $920 million just on costumes for their pets. That is nearly a billion dollars so that dogs and cats can dress up for a holiday they do not even know exists. The most popular pet costume, in case you were wondering, is a pumpkin.

Why does candy cost more these days?

If your family has noticed that a bag of candy seems pricier than it used to be, you are not imagining it. Part of the reason is cocoa, the main ingredient in chocolate, which has gotten a lot more expensive in recent years. When it costs more to make something, that cost usually gets passed along to shoppers. That is inflation at work, the same idea we explored in our article on rising prices, showing up right in your Halloween bucket.

The real trick behind the treats

Here is the part that makes Halloween such a fascinating business story. Stores do not just wake up on October 1st and hope people buy candy. They plan for this for months. Candy companies run their factories overtime through the summer. Costume shops order their inventory in the spring. Stores clear out whole sections to make room for pumpkins and fake spiderwebs, all betting that you will show up and spend.

Why does it work? Supply and demand. Millions of people all want the same things, candy and costumes, at the exact same time of year. When demand spikes like that, it becomes a giant opportunity for businesses. For some candy and costume companies, these few weeks are the most important of the entire year. In a way, Halloween is not just one holiday. It is a whole season that businesses spend all year preparing for.

The takeaway

So this Halloween, as you pull on your costume and fill your bag with candy, remember that you are part of a $13.6 billion machine. Every piece of candy, every decoration, and every goofy pet costume is a tiny part of one of the biggest shopping seasons of the year. The scariest thing about Halloween might just be how much money it moves.

Not bad for a holiday about pretend monsters.