In early afternoon trade, the S&P/ASX 200 Index (ASX: XJO) is on course to finish the year with another decline. At the time of writing, the benchmark index is down 0.7% to 8,174.7 points.

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

DroneShield Ltd (ASX: DRO)

The DroneShield share price is up 5.5% to 75.5 cents. This is despite there being no news out of the counter drone technology company this week. However, with its shares pulling back meaningfully from recent highs, it seems that some investors believe that a buying opportunity has been created. Bell Potter certainly thinks this is the case. Its analysts recently put a buy rating and $1.20 price target on DroneShield's shares.

Invictus Energy Ltd (ASX: IVZ)

The Invictus Energy share price is up almost 7% to 8 cents. This morning, this independent upstream oil and gas company revealed that the second tranche of a US$10 million institutional placement at 10 cents per new share has been completed. And due to strong demand, the company also accepted an additional US$2 million in oversubscriptions on the same terms. Invictus Energy's managing director, Scott Macmillan, said: "The completion of this strategic capital raise is testament to the strong investor confidence in our Cabora Bassa Project and its potential to drive transformative growth in Zimbabwe's energy landscape. We are grateful for the enduring and overwhelming local and institutional support."

Mesoblast Ltd (ASX: MSB)

The Mesoblast share price is up almost 10% to $3.18. This follows a huge gain by the biotechnology company's NASDAQ listed shares overnight. This appears to have been driven by excitement over the recent approval of one of the company's stem cell therapies. Last week, the US FDA approved its Ryoncil (remestemcel-L) product as the first mesenchymal stromal cell (MSC) therapy in the United States. Ryoncil is the only MSC therapy approved in the U.S. for any indication. It is also the only approved therapy for steroid-refractory acute graft versus host disease (SR-aGvHD) in children 2 months and older.

Weebit Nano Ltd (ASX: WBT)

The Weebit Nano share price is up 4% to $3.60. This gain comes despite there being no news out of the semiconductor company. Though, it is worth noting that Weebit Nano's shares have been on a strong run recently. So much so, they have risen almost 90% since this time three months ago.