Inflation concerns drove much of the trading activity in US shares throughout May, with the impact being felt in different measures across the various segments of the market. 

By the end of the month, the industrials-based Dow Jones had advanced 1.9%, outperforming the S&P 500, up 0.6%, and well in front of the tech-heavy Nasdaq, which shed 1.5% on the back of a sell-down in mega-tech names.

What US shares were Selfwealth members trading last month? Let take a look.

Which US shares were the most held?

With an almost unassailable lead atop the charts of the most-held US stocks across the Selfwealth community, interest in GameStop (NYSE: GME) showed no signs of slowing. While the stock surged 27.9% throughout May, the collective value of Selfwealth members' holdings in GME rocketed 45.5%, indicating existing investors continue to accumulate and new investors jumped on board the Reddit favourite.GME wasn't the only stock to see a huge month-on-month jump in interest, with AMC Entertainment (NYSE: AMC) and ARK Genomic Revolution ETF (ARKG) also recording similar movements.

In the case of AMC, the movement can be traced easily enough back to a rocketing performance from the head stock during the month, up over 160% as another Reddit-inspired short squeeze takes hold. This trend has continued in the early days of June as well. 

On the other hand, ARKG eased about 8% in May, indicating growth in holdings has come from investors buying into the dip. With the stock at one point trading at its lowest level since November last year, that may have encouraged investors to take up a position. 

Tech and innovation continue to be the resounding themes coming through in terms of portfolio exposure, with consumer electronics, software, chip-makers, ecommerce and digital payments the most-prominent industry groups. In fact, the only name outside of the tech and innovation thematic that made the top 10 in April, Berkshire Hathaway (NYSE: BRK.B), fell out of the list in May. BRK remains the only non-tech name in the top 20 most-held US stocks across the Selfwealth community.US StockCompany1GMEGameStop2TSLATesla3AAPLApple4ARKKARK Innovation ETF5AMZNAmazon6MSFTMicrosoft7PLTRPalantir8AMCAMC Entertainment9NIONio10ARKGARK Genomic Revolution ETF11BRK.BBerkshire Hathaway12GOOGLAlphabet13BABAAlibaba14QQQInvesco QQQ Trust Series 115ARKFArk Fintech Innovation ETF16AMDAdvanced Micro Devices17PYPLPayPal18NVDANvidia19SQSquare20TSMTaiwan Semiconductor Manufacturing

US share trading activity

Nio (NYSE: NIO), despite just one-tenth the number of trades as that of highly-popular GameStop (NYSE: GME), was the most-traded US stock by value last month. The stock actually shed about 3% over the course of May, however, increasing enthusiasm for the development of electric vehicles has acted as a catalyst, something that has also garnered further interest in Tesla (NASDAQ: TSLA).Both Uber (NYSE: UBER) and Airbnb (NASDAQ: ABNB) hit multi-month lows in May, which seemingly brought on higher trading activity. The two household names haven't featured all that consistently among the most-traded names in the Selfwealth community, and trade numbers for both stocks were relatively modest. Nonetheless, activity was largely driven by a select number of investors with high conviction in these peer-to-peer platforms.Elsewhere, Alibaba (NYSE: BABA) commanded the highest buy-to-sell ratio in terms of the value of orders filled through the Selfwealth platform. That came despite Alibaba shares sinking on the company first quarterly loss as a public company, and ongoing concerns surrounding its regulatory outlook in the wake of Jack Ma public spat with the Chinese government late last year. Selfwealth members appear content to bank on a long-term turnaround in the ecommerce business.One name that local investors might not be used to seeing is ProShares Ultra VIX Short Term Futures ETF (UVXY). This is a complex and leveraged ETF that tracks the S&P 500 Short-Term VIX Futures Index, a basket of VIX futures across different months, essentially acting as a measure of volatility across the market.Unsurprisingly, not only is tech a centrepiece of long-term investors' portfolios, but it has also been the major focal point among active traders. Mega-tech names like Apple (NASDAQ: AAPL) and Microsoft (NASDAQ: MSFT) were both at the top of the list in terms of the value of shares exchanged, and also by the number of orders filled. Meanwhile, chip-makers like Nvidia (NASDAQ: NVDA) and Advanced Micro Devices (NASDAQ: AMD) again courted major trading interest amid global supply chain issues that have impacted a number of industries.Top 20 stocks traded by valueCode SecurityBuy-sell Ratio1NIONio52.1%2GMEGameStop67.2%3UBERUber57.6%4TSLATesla73.8%5SQQQProShares UltraPro Short QQQ ETF40.0%6AAPLApple76.2%7UVXYProShares Ultra VIX Short Term Futures ETF50.0%8AMCAMC Entertainment60.9%9OCGNOcugen48.0%10ARKKARK Innovation ETF68.1%11AMZNAmazon81.7%12BABAAlibaba86.9%13MSFTMicrosoft79.4%14PLTRPalantir84.2%15ABNBAirBnb67.1%16NVDANvidia67.1%17CZRCeasars Entertainment50.4%18ZIZoomInfo Technologies65.8%19AMDAdvanced Micro Devices71.6%20DQDaqo New Energy Corp51.2%

That all for this Trade Trends report, stay tuned for the next edition this time next month!