The next hundred dollars you put in the market can be a game changer. There is no investment that is too small these days. There are plenty of places offering commission-free trading. Even a stock with a high price point isn't a barrier anymore. A growing number of brokers let you buy fractional shares so you don't have to buy entire shares to put more of you money to work.

Where should you invest $100 right now? I have three investment ideas -- Sirius XM Holdings (NASDAQ:SIRI), Vanguard Consumer Discretionary ETF (NYSEMKT:VCR), and Amazon.com (NASDAQ:AMZN) -- that could be solid additions to your portfolio. Let's take a closer look at the three investments. 

A hundred-dollar bill folded into a paper airplane ready to be thrown into the sky.

Image source: Getty Images.

Sirius XM Holdings

Satellite radio is starting to bounce back along with the automotive industry. We're driving again, and earlier this week we saw Sirius XM post its strongest year-over-year organic revenue growth in 11 years.

Sirius XM now has 31.4 million premium subscribers on its platform, and the 1.1 million net additions it expects to score this year will be its strongest showing since 2018. Sirius XM is a logical winner of the economy reopening, it pays out a dividend, and it's also going to seem magnetic to investors with a little money to put to work because of its low share price. 

Sirius XM is a 134-bagger since bottoming out in 2009, but it's still trading below $7 a share. You don't need to focus on low-priced stocks if you have just $100 to invest. We already went over the growing popularity of fractional shares. However, if you're going to look at stocks with single-digit price points this is one worth considering as its business is bouncing back, and it even has a quarterly dividend that has gone up every year since it initiated a distribution policy five years ago.  

Vanguard Consumer Discretionary ETF

A great way to put a little money to work on a large basket of stocks is a low-cost index ETF. Vanguard runs some of the best-known index mutual funds, and it's been approaching the same market with its exchange-traded funds

Vanguard operates some of the market's favorite ETFs, but let's dive down to an industry that I think is going to beat the market from here. Vanguard Consumer Discretionary ETF tries to duplicate the MSCI US Investable Market Index/Consumer Discretionary 25/50, an index of large, mid-size, and small U.S. companies in the consumer discretionary space.

Amazon -- which we will get to shortly -- is its largest holding at nearly 23% of its net assets. The online retailer tops a list of other consumer brands that should thrive as we claw our way out of the global COVID-19 crisis. The expense rate is low at 0.10%, and that means there's even enough left over for a current yield of 1.3%. Yes, you can own chunk of Amazon and get a dividend, too.  

Amazon 

The leading online retailer posts its second-quarter results on Thursday afternoon, and it should be another strong report. Amazon was already rolling -- net sales soared 38% last year, accelerating to 44% in the first quarter of this year -- but the market darling is just getting started. 

Thursday's report will benefit from Amazon's recent momentum and also from Prime Day shifting to the second quarter of this year. Amazon's here to provide some balance to Sirius XM. Unlike Sirius XM with its sub-$7 share price, Amazon's trading well into the four figures. Naturally you would have to buy Amazon through a broker that allows fractional shares. Amazon's not cheap by most measuring sticks, but it could be higher after another blowout quarterly performance by the end of the week.   

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.