The S&P/ASX 200 Index (ASX: XJO) had a strong start to 2025. Over the course of January, the benchmark index rose 4.6% to end at 8,532.3 points.

A good number of ASX 200 shares rose with the market last month, but a few stood out with particularly strong gains.

Here's why these were the best performers on the index in January:

Boss Energy Ltd (ASX: BOE)

The Boss Energy share price was the best performer on the ASX 200 in January with a gain of 36.2%. It was a volatile but positive month for this uranium producer. Optimism over artificial intelligence (AI)-fuelled nuclear power adoption was briefly overshadowed by an AI selloff following the emergence of DeepSeek. Then a strong quarterly update late in the month helped rebuild positive investor sentiment and may have led to short sellers buying shares to close their positions.

Emerald Resources NL (ASX: EMR)

The Emerald Resources share price was a strong performer and recorded a gain of 33% for the period. Investors were buying this gold miner's shares after it revealed a record operational performance at its Okvau operation in Cambodia. Gold production for the December quarter was 31,888 ounces, which exceeded its guidance of 25,000 ounces to 30,000 ounces. A record gold price also gave its shares a boost.

Liontown Resources Ltd (ASX: LTR)

The Liontown Resources share price wasn't far behind with a gain of 27.4% in January. The catalyst for this was the release of the lithium miner's second quarter update. Liontown reported a 215% quarter on quarter increase in spodumene concentrate production to 88,683 dry metric tonnes (dmt) for the three months. This supported a 651% increase in spodumene concentrate shipments to 81,341 dmt and a 674% jump in total revenue to $89.8 million. The company also revealed that it achieved net cash from operating activities of $16.7 million for the period.

Insignia Financial Ltd (ASX: IFL)

The Insignia Financial share price was on form and raced 24.8% higher during January. Investors were buying this financial services company's shares after a bidding war broke out between CC Capital Partners and Bain Capital. In December, Insignia received and rejected a $4.00 cash per share non-binding offer from Bain Capital. By the end of January, both Bain Capital and CC Capital had made offers of $4.60 per share. This is 15% higher than the original offer. Both parties have been granted limited due diligence access.