February has seen many of the UK’s favourite Stocks and Shares ISA picks still appearing in the monthly top 10 lists. But investors are turning towards a couple of intriguing options that catch my eye.

And don’t forget, we’re heading into the last full month before the ISA deadline, so we need to get our choices in order soon if we want to top up our ISAs before time runs out.

So which FTSE 100 shares do UK investors favour now?

February top picks

RELX (LSE: REL) has been creeping up the ISA popularity lists, as its share price has been sliding. It’s down 47% since its 52-week high of May 2025. And the share price dropped sharply as we headed towards full-year results on 12 February — which turned out solid.

Revenue increased 7%, adjusted operating profit perked up 9%, and adjusted earnings per share jumped 10%. The company lifted the dividend 7%, well ahead of inflation. RELX returned £1.5bn to shareholders via share buybacks over the year. And we should expect a further £2.25bn in 2026.

As with so many share price upsets these days, AI lies behind the drop — made worse by Anthropic’s Claude legal chatbot release. Nobody can have missed the software sell-off that’s hit more traditional tech stocks across the board.

The future is likely to see RELX sentiment pulled two ways. In the positive direction we have long-term customers who rely on human-led trust, with a well-proven track record. That can be especially important in RELX’s legal data offerings. Against that we have the promise of cheap and fast AI services, and the hope that the proportion of misleading slop they churn out will diminish.

Optimists see AI as an opportunity for companies to incorporate it and offer the best of both worlds. Investors who feel like that should consider RELX while the shares are down, I reckon.

Suffering softies

The Sage (LSE: SGE) share price trajectory closely follows RELX, for the same reason. Sage has for years been a number one pick for business and accounting software. And yes, the AI beast is threatening to take the food from the mouths of human software developers here too.

But it hasn’t held Stocks and Shares ISA investors back. And Sage made a new entry in interactive investor’s top 10 ISA list in February.

We’ll have to wait until May to see how the first half of Sage’s current financial year goes. But in January’s first-quarter update, CFO Jacqui Cartin reported “a strong start to FY26, with Q1 organic revenue growth accelerating to 10%.” And she reiterated full-year guidance from November’s 2025 full-year results.

Back then, management spoke of organic revenue growth of 9% or better. Operating margins were “expected to continue trending upwards in FY26 and beyond.“

Is this another company that could embrace AI and use it for future growth rather than being made redundant by it? I see a good chance of it. And I rate Sage as another that long-term ISA investors should consider. Just beware of the AI threat too.