I did more than just a little holiday shopping on the final trading day of 2018. I bought into five stocks and an index fund on Monday. I haven't gone on that kind of one-day shopping spree in years.

These are scary times, and I get it. There are a lot of unknowns out there. I still felt that the time was right to buy into this volatile market at the tail end of one of its worst quarters. Let's go over some of the reasons I wanted to get in ahead of whatever 2019 brings our way.

A roll of hundred-dollar bills with a green ribbon.

Image source: Getty Images.

1. Stocks are a lot cheaper now

The combination of rising earnings and sinking equity prices should be a dog whistle for value hounds and a dinner bell for everybody else. Profitability was poised to pop in 2018 as a result of corporate tax rates coming down, and that's just what happened. Earnings for the S&P 500 companies soared 41% in 2018, according to Barron's

The S&P 500 only moved 6% lower for the year. The market's 14% slide over the past three months came after a more robust start through the first three quarters of 2018. However, the end result of buoyant net income and a slight dip in price tags leaves the S&P 500 -- trading for 23 times trailing earnings a year ago -- fetching a multiple of less than 15 now. 

Bears will argue that the surge in earnings is a one-time event, and that's fair. Bottom-line growth will have to be earned in 2019, but that still doesn't take away from stocks trading at reasonable multiples. 

2. History is kind after a brutal quarter

The S&P 500 plummeted 14% in December, but the market has typically bounced back after a rough three-month run. Bespoke Investment Group took a look at the last few times that the market suffered a double-digit percentage hit, and the results are kind to the opportunistic investors buying when everyone else is selling. 

The S&P 500 has suffered double-digit percentage slides in a quarter three other times over the past 10 years, only to bounce back with double-digit percentage gains the following quarter. A year later from those three brutal quarters, the S&P 500 was trading 47%, 28%, and 27% higher. 

The favorable math doesn't end there. The last five times that the market has fallen by at least 10% in a single quarter the market has traded at least 22% higher a year later. You have to go back more than 16 years to find the last time the market wasn't higher a year after a double-digit drop. 

Momentum isn't pretty now, but it also wasn't much of a looker each of the five previous times that this happened. History trumps momentum here. 

3. Bargains are there for the picking

Facebook (NASDAQ:FB) was not one of the stocks I bought earlier this week, but let's talk about the social networking behemoth that has seen its shares plummet 26% in 2018. Facebook's namesake site has been a notoriety factory over the past year, but this is also the same company behind Instagram, WhatsApp, and Messenger -- some of the world's hottest and ascending apps. 

Facebook's flagship site is till a hotbed that's unmatched with its 2.27 billion monthly active users. Revenue has risen 42% over the trailing 12 months. It's easy to fathom why Facebook wouldn't be a market darling, but to see the stock shed more than a quarter of its value in a year in which it continues to grow its social app empire is amazing. 

I also didn't buy AT&T (NYSE:T) on Monday, but I have on two separate occasions in 2018. The telco giant isn't at its best right now, as strength in its thriving wireless business is being held back by struggles at its legacy businesses and millennials bailing on DirecTV. AT&T still managed to bump its dividend higher last month, something that it has now done for 35 consecutive years. The stock is yielding 7.1%. It's highly likely to boost its payout again by the end of this year, and that means that either the stock moves higher or it doesn't and its yield a year from now will be a lot higher than 7.1%. 

There are bargains out there. History is on the side of the buyers. We'll see how right or wrong I am a year from now.

Check out the latest Facebook and AT&T earnings call transcripts.