There has been a resurgence of meme stocks over the last few weeks, could there be another trend emerging? 
Reddit has been a hot topic, with their public listing debut on March 21st. $Reddit(RDDT.US)$ stock rose more than 120% from its IPO price at its high, however in the last week it has dropped around 40% and is sitting at $45.  
Another new meme stock from the social media space is Trump Media, which recently went public via a SPAC merger. Like Reddit,  $Trump Media & Technology(DJT.US)$ 59% on it...

$NIO Inc(NIO.US)$ BBB?

The financial story of 2021 may be the 445 exchange trade funds that debuted this year as the U.S. ETF industry ballooned to $7 trillion.
The business has never known times like these. A corner of Wall Street already enjoying a reputation for explosive growth has gone supernova, with a record 445 new products in 2021 so far.
--- according to Bloomberg
Behind the rapid expansion is a deluge of new cash as investors chase an economic recovery from the coronavirus, while equity mutual funds fall out of favor. About $900 billion has flowed into the ETF market since the start of the year -- also easily a record. Barely any funds are getting shuttered.
There's a lot of money being transferred from a generational standpoint. The stars are aligning right now for the ETF industry to a) evolve very quickly and b) take in flows.”
--- said Keith Buchanan, portfolio manager at Globalt Investments
All that means the number of ETFs Americans can choose from has jumped 19% since the end of 2020. About a quarter of all trading ETFs are less than two-years old, according to Bloomberg Intelligence -- another sign of industry boom times.
Active ETF is growing
The details of the launches tell a deeper story: From the 445 new arrivals, 75 target fixed income. For the first time, new actively managed ETFs outnumber their passive counterparts with 298 debuts versus 147.
The letters ETF used to spell passive to most investors. Now more and more advisors are realizing that ETFs are no longer just about gaining passive exposure and that active ETFs, particularly within fixed income, make sense because they can gain exposure to experienced bond managers.”
--- said Allison Bonds, head of private wealth management at State Street Global Advisors
At the same time, launches of low-cost, broad equity-index trackers are dwindling. Traditional core or "beta vehicles" made up only 8% of total equity ETF launches from the start of.
--- according to Bloomberg Intelligence
Partly, that's because such core strategies are well represented by big, established and very cheap funds from the major issuers. The popularity of the likes of the $SPDR S&P 500 ETF(SPY.US)$ and the $Vanguard S&P 500 ETF(VOO.US)$ mean they still claim the lion's share of new cash.
Thematic ETF become popular
Thematic ETF target trends like automation or electric vehiclesrather than traditional industry segments. They've proved hugely popular with the retail-investing crowd, which has been a growing force in markets since the pandemic hit. The high-profile success of Cathie Wood's Ark Investment Management $ARK Innovation ETF(ARKK.US)$ $ARK Autonomous Technology & Robotics ETF(ARKQ.US)$ has also helped fuel a wave of copycats $ProShares Bitcoin Strategy ETF(BITO.US)$ $Valkyrie Bitcoin and Ether Strategy ETF(BTF.US)$.
Complex Categories
Aligned with this specialization, funds have been getting more complex. Over 30 ESG ETFs have launched in the U.S. this year. There have been 56 new ETFs this year investing in derivatives to amplify bets, make them inverse or deliver protection. A major driver of this has been the development of defined-outcome ETFs, also know as buffers. They seek to provide capped exposure to gains in exchange for limiting losses.
Source: TheStreet, Bloomberg