Stockstream lets Twitch viewers buy and sell stocks using an Amazon engineer's $50,000 initial investment. Here it is on the late afternoon of 6/29/2017. Screenshot/Business Insider In late May, Amazon engineer Mike Roberts unveiled Stockstream — an experiment in letting viewers of his Twitch livestream play the stock market with $50,000 of his own money.

A month later, and the experiment is still going strong. Over the course of 2,125 trades, Stockstream players have voted to pick out a diversified portfolio that now includes a handful of shares in Ford, Costco, Apple, and GE, among many others.

"I'm actually quite surprised/pleased with how well the portfolio has been doing," Roberts tells Business Insider.

As of Thursday afternoon, Stockstream was hovering around a zero percent return on Roberts' original $50,000 investment. That doesn't sound very impressive, but it's actually a better performance than the roughly 1% dip in the Nasdaq Composite over the last month. For comparison, the Dow Jones Industrial Average posted a 1.22% gain in the same period, but still not bad for a Twitch experiment.

The way StockStream works is simple: Every five minutes, a round of voting opens, allowing Twitch viewers to vote on the purchase or sale of any stock, like "!buy AAPL" or !sell TSLA." After five minutes, the relevant stocks get added to or subtracted from Roberts' portfolio, with the trade executing via the popular Robinhood app.

It's another kind of victory, too: Roberts himself was fearful going into the Stockstream experiment that trolls might conspire to ruin his fun. Now, it looks like the Stockstream portfolio is at least resilient enough to withstand the turbulence of the public markets over the last few weeks. The Stockstream portfolio's status, as of an hour after the closing bell on Thursday. It includes the $500 or so in free stocks given via the Robinhood app. Screenshot/Business Insider

Still, there are some pranksters out there: While he can't be sure, Roberts says that he's pretty sure that players' fondness for buying ProShares (symbol: DOG), Cheesecake Factory (CAKE), Maui Land & Pineapple Company (MLP, the same acronym as "My Little Pony") and cruise ship company Carnival (CUK, similar to "cuck," the alt-right's favorite insult) is intended as some kind of joke.

The good part is that as troll moves go, this is pretty harmless, and hasn't ruined his or anybody else's fun. Stockstream has even attracted a small community on Discord, a popular chat app for gamers.

"For the most part it seems people are playing in good faith and having fun, I haven't had to ban anyone recently, and the Discord channel usually has a bit of discussion each day on various stocks and plays," says Roberts.