The FTSE 100 index has risen an incredible 17% so far in 2025. While I’m surprised by some of its strongest performers — Lloyds and BP, I’m looking at you — I’m not shocked by the stunning gains some other UK blue-chip shares have enjoyed.

Take Aviva (LSE:AV.) and Games Workshop (LSE:GAW). These FTSE firecrackers have risen a stunning 36% and 46% respectively since 1 January. I’m convinced they can continue their impressive ascents too.

So much so, in fact, that I’ve bought both of them for my own portfolio.

But what could thrust these top stocks to new price highs and makes them worth considering? Let’s take a look.

Forecast beater

Aviva’s origins go all the way back to 1696. In that time, it’s established itself as one of the UK’s most trusted brands.

In an industry dealing with people’s money and financial security, it’s a quality that can’t be overstated. It’s enabled the company to build a 25m-strong global customer base. It’s also the bedrock of Aviva’s resilience in what are tough conditions for the financial services industry.

For 2025, it’s on course to grow operating profit 25% year on year (stripping out its acquisition of Direct Line).

Aviva isn’t just surviving, it’s thriving. And that’s thanks in large to the firm’s focus on capital-light businesses and a cost-cutting plan that’s smashing expectations. Operating profit and cash generation targets have been hit a year ahead of schedule, leading to ambitious new three-year targets released a month ago.

This includes average operating earnings per share (EPS) growth of 11% between this year and 2028.

There are challenges here, like intense competition across its markets. The business could also suffer in the event of adverse regulatory changes.

Yet Aviva’s operational excellence and huge market opportunities still make its shares a top buy. It’s in great shape to grow earnings as population ageing and the growing importance of financial planning drive sales.

One final thing: with a forward price-to-earnings growth (PEG) of 0.1 and 6% dividend yield, Aviva’s share price is dirt cheap.

A model stock

At the other end of the scale, Games Workshop’s shares look pretty pricey on paper. Its forward price-to-earnings (P/E) ratio of 35 times sails above the FTSE 100 average of 12.3 times.

A valuation like this could see the stock sink if trading news is anything less than spectacular. Given the tough consumer landscape and specific market threats (like growing competition and counterfeiting), such a scenario is certainly possible.

Yet the Warhammer manufacturer is showing no signs of slowing down. In fact, like Aviva it continues to surpass expectations, announcing it expected core sales growth of 15% this year.

In my view, the company is more than deserving of its premium rating.

Games Workshop sits at the top of the tabletop gaming world. This is a niche hobby, but it’s a rapidly growing one where demand remains stable even when consumers feel the pinch. Its miniatures and games systems consistently sell in vast quantities to both casual and hardcore fans.

What’s most exciting me is its plans to accelerate IP licensing deals with media companies. Moves like the TV and licensing deal it’s inked with Amazon could supercharge earnings growth over the next decade.