December certainly was a great month for the S&P/ASX 200 Index (ASX: XJO). The benchmark index rose 2.6% over the period to end it at 7,444.6 points.
Unfortunately, not all shares were able to climb higher with the market. Here's why these were the worst performing ASX 200 shares in December:
Magellan Financial Group Ltd (ASX: MFG)
The Magellan share price was the worst performer on the ASX 200 last month with a 34.4% decline. Investors were selling off the fund manager's shares after it announced the termination of the St James's Place mandate. Magellan advised that the mandate represents approximately 12% of the company's current annual revenues. Though, due to the timing of its termination, it is only anticipated to impact Magellan's FY 2022 revenues by 6%. Investors appear concerned more mandates could be lost, particularly given the very poor performance of its flagship fund.
Afterpay Ltd (ASX: APT)
The Afterpay share price was some way behind as the next worst performer with a decline of 17%. The buy now pay later (BNPL) provider's shares were sold down after the Square share price tumbled lower. As Afterpay shareholders have voted in favour of being acquired by Square in an all-scrip deal, its shares rise and fall with the Square share price.
Mesoblast Limited (ASX: MSB)
The Mesoblast share price was a poor performer and dropped 12.7% during the month. Investors were selling off the allogeneic cellular medicines developer's shares after Novartis terminated an agreement that could have been worth ~US$1.2 billion. The two parties were looking at Mesoblasts' remestemcel-L as a treatment for acute respiratory distress syndrome (ARDS) due to COVID-19. Novartis ended the agreement after reviewing some disappointing trial results.
Zip Co Ltd (ASX: Z1P)
The Zip share price was out of form again and dropped 11.5% last month. This was driven by weakness in the tech sector and concerns over news that US authorities are launching an investigation into the BNPL sector. The US Consumer Financial Protection Bureau is looking to see if BNPL players need to be better regulated and if US consumers are adequately protected.