The S&P/ASX 200 Index (ASX: XJO) is having a day to forget on Monday. In afternoon trade, the benchmark index is down 4.3% to 7,336.6 points.

Four ASX shares that are not letting that hold them back are listed below. Here's why they are rising:

Abacus Storage King (ASX: ASK)

The Abacus Storage King share price is up 19% to $1.38. This morning, this self-storage company revealed that it has received a takeover offer from a consortium made up of Ki Corporation Limited and NYSE-listed giant $Public Storage(PSA-N)$ (NYSE: PSA). An offer of $1.47 per share, less any declared distributions, has been tabled. This represents a 27% premium to where its shares finished last week. The company stated: "ASK has formed an independent board committee consisting of ASK's independent directors and it has commenced an assessment of the Indicative Proposal but has not at this stage formed any view on its merits."

Cettire Ltd (ASX: CTT)

The Cettire share price is up 3.5% to 64.7 cents. This is despite there being no news out of the online luxury products retailer. However, with its shares down by a third since this time last month and over 80% since this time last year, it is possible that bargain hunters are swooping in today. In addition, as one of the most shorted shares on the ASX, it is possible that some short sellers are buying back shares today in order to close their positions and lock in their gains.

Challenger Ltd (ASX: CGF)

The Challenger share price is up 7% to $5.92. Investors have been buying the annuities company's shares today following news that TAL Dai-ichi Life Australia has agreed to acquire a 15.1% minority interest in the company from MS&AD Insurance Group Holdings. TAL is paying 763 yen per Challenger share, which is the equivalent of approximately A$8.46 per share. That's a hefty 52.7% premium to Friday's closing price. Challenger's CEO, Nick Hamilton, said: "Dai-ichi Life is a global leader in life insurance and we look forward to building a relationship that will benefit both our customers and shareholders. We welcome their significant investment in our business and will explore future opportunities that support our strategic objectives."

Lynas Rare Earths Ltd (ASX: LYC)

The Lynas share price is up almost 3% to $7.52. This may have been driven by news that China has expanded its use of critical minerals as a trade weapon with curbs on exports of rare earths. According to Bloomberg, this is part of its retaliation to US President Donald Trump's reciprocal tariffs on imported Chinese goods.