More evidence that the economy continued to chug along came this week when the Institute for Supply Management said its non-manufacturing index jumped 110 basis points from January to February, and reached 57.6%. For context, any rating above 50% means more businesses are expanding. The 57.6% rating was the highest since October 2015, and the expansion of 16 of the 18 sectors was the highest number since the middle of 2014.

In broader news, the S&P 500 finished with its sixth-consecutive weekly gain, and the Dow tallied its fourth-consecutive weekly gain. All that aside, there were some major headlines and moves in the markets this week. Let's hit some highlights.

A successful IPO

Image of Wall Street street sign with an American flag in the background.

Image source: Getty Images.

If you're an investor, or just casually follow the markets, chances are you heard about Snap Inc.'s (NYSE:SNAP) successful IPO on Thursday. The company announced a day prior to the IPO that it would sell 200 million shares for $17 per share, which was the largest U.S. IPO since 2014. Although the company has never turned a profit, investors jumped on board the IPO wagon, sending its shares up 44%, to $24.48, when shares hit the market on Thursday.

The IPO made a lot of people rich, including Snap CEO Evan Spiegel, who sold at least $272 million worth of shares and still owns roughly $3.6 billion, according to MarketWatch. Snap's IPO raised almost $2.5 billion for the parent company and another $1 billion for the founders and early investors.

But now the real work begins, because Snap just as easily could go the way of Twitter, which declined consistently after its IPO, rather than Facebook, which became a tech juggernaut in the years following its IPO. Snap has roughly 158 million users -- mostly between the ages of 18 and 24 -- and is growing.

Now, it's just a matter of if and when Snap can better monetize its growing user base consistently. This is a task much easier said than done -- just ask Twitter.

Bad optics

Every kiss begins with Kay, but that brand image might not be what consumers and investors think of first for Signet Jewelers Ltd (NYSE:SIG), the owner of Kay Jeweler and Jared, among others. The Washington Post reported that hundreds of former employees claimed the company's CEO and other management members allowed a corporate culture of sexual harassment and discrimination.

The attorneys were only granted permission to release the statements publicly Sunday, and the headlines sent shares of Signet Jewelers stock down roughly 13% during intra-day trading on Tuesday. No matter how you slice the issue, it's bad for the jewelry company, especially in today's easily offended and social-media-intensive world.

Going forward, a class-action hearing is scheduled for early next year, when witnesses will be called to testify before an arbitration judge for the first time. Currently, Signet Jewelers trades at a forward price-to-earnings ratio of eight, per estimates, which could tempt value investors. If you find yourself in that camp, buyer beware -- this will be something to watch over the next couple of years.

An aging dinosaur

Shares of video game retailer GameStop (NYSE:GME) received yet another reminder that its business is going to be an uphill battle as more consumers opt to purchase video games online. On Tuesday, Microsoft (NASDAQ:MSFT) announced a subscription service for Xbox One that will give full access to over 100 older video games.

The service, named Xbox Game Pass, gives consumers another way to pass the GameStop brick-and-mortar stores, and could easily create a headwind for the game company's sales of both new and used video games. Investors were quick to react to Microsoft's announcement and sent GameStop shares quickly down 10% during intra-day trading.

In my opinion, GameStop is an aging dinosaur that looks to be heading the way of Blockbuster in an increasingly digital world. The company's top and bottom lines have been stagnant since 2010. Without a growth story, in addition to an increasingly digital world, there doesn't seem to be much value left in owning shares. So it's no surprise that the company trades at a paltry 6.7 times forward earnings, per estimates.

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.