There were a number of delays for some of the ASX names scheduled to list over recent days, with the market operator pushing them back to next week. It was, however, largely a positive week for the names that did make it onto the exchange.

Overseas, most of the stocks lining up at the boards this week were medical stocks, but one Australian-founded celebrity-backed name stole the headlines as it finally rang the bell for its market debut.

New ASX listings

Copper and gold explorer Resource Base (ASX: RBX) struggled to gain traction after completing its $5 million offer. With its Black Range project in Victoria, acquired from Navarre Resources (ASX: NML), the company is hoping to establish an inferred JORC by the end of 2021. Early trading in RBX shares has seen the stock price trade about 10-15% below the company ipo price.It was a solid debut for engineering, procurement and construction services company Aerison Group (‹ASX: AE1), which raised $13.5 million. The Perth-based company, with more than 30 years of operating history and an order book of more than $300 million proved a hit as it embarks on east coast growth aspirations. The stock gained 30% in its first week as a public company on the ASX.Successful listings also came from Industrial Minerals (ASX: IND) and Balkan Mining and Minerals (ASX: BMM), which both climbed by more than 80% at one stage. 

Industrial Minerals is an early-stage explorer of high-purity silica sand, gypsum, salt, construction sand and aggregates. With more than 70% of the company shares on issue at debut held by its top 20 shareholders, the listing performed well throughout the first week after raising $5 million. 

Meanwhile, Balkan Mining and Minerals is another resources company focused on the early-stage exploration through to development of borate and lithium in the Balkans region. It took out the honours this week as the best-performing ASX ipo.

Interest in gold explorer Mt Monger Resources (ASX: MTM) was fairly muted after its listing, with the stock trading mostly flat.

New US listings

Perhaps the most high-profile listing of the week came from abroad, and with celebrity backing too.

Fitness studio chain F45 Training Holdings (NYSE: FXLV), which was founded in Australia back in 2013 and now boasts 1,800 franchised fitness studios and the backing of Hollywood star Mark Wahlberg, priced its ipo at US$16 per share to give it an expected value of US$1.4 billion on listing. The stock opened modestly higher, above US$17 per share, before sliding to end its first day of trading just 1.2% above the offer price.

Elsewhere, it was a volatile debut for kidney disease biotech Unicycive Therapeutics (NASDAQ: UNCY), which has shed around 25% of its market cap since listing, despite at one stage opening more than 70% above its ipo price of US$5 per share. The company, which is in late preclinical stage, is developing a drug treatment for kidney diseases called Renazor, a novel phosphate binding agent to treat hyperphosphatemia. Another medical-oriented stock facing troubles in its early days of trading is Sera Prognostics (NASDAQ: SERA). The company, which develops diagnostic tests for pregnancy complications, raised $75 million via 4.7 million shares priced at US$16 each. However, it is currently more than 25% off that price, with the stock slumping on debut.Contrasting that picture was a strong listing from eye device company Sight Sciences (NASDAQ: SGHT). It raised US$240 million at US$24 per share, with its ipo size expanded amid pre-listing demand. A provider of medical and surgical devices for under-served eye conditions, Sight Sciences rose nearly 40% during trading last night. Similarly, Rapid Micro Biosystems (NASDAQ: RPID), a provider of automated microbial testing devices and platforms, climbed 7% upon listing. Having raised US$158 million at US$20 per share, the company is looking to roll-out its Growth Direct microbial testing platform, which it says can be used for quality control purposes with vaccinations, cell and gene therapeutics, sterile injectables, and other procedures.The last of this week initial public offerings are expected to list on the US stock market tonight, including Italian vaccine vial marker Stevanato (NYSE: STVN), which has raised US$672 million at US$21 per share, and digital lending platform Blend Labs (NYSE: BLND), which has successfully secured US$360 million at the top of its price range, at US$18 per share.