Are these three leading insurers a buy after recent results?

In 24 June the aftermath of the Brexit vote, shares in Standard Life(LSE: SL), Legal & General(LSE: LGEN) and Aviva(LSE: AV) plunged as investors, fearing for the worse for the UK economy, dumped financial stocks across the board.

///>

However, since the end of June these leading insurers have all published upbeat trading statements for the first half. What's more, the managements of Standard, Legal and Aviva have all informed investors that their companies are well placed to ride out any Brexit turbulence.

But despite these comments and the positive trading statements, shares in Standard, Legal and Aviva are still trading 1%, 13.1% and 5.8% respectively below the level they were on the eve of the Brexit vote, which could be a great opportunity for the long-term Foolish investor.

Undervalued

Yesterday Standard announced an 18% increase in operating profit for the first half of the year. Fee-based income for the group rose to £794m from £761m year-on-year and total operating income jumped by £56m to £857m. Total assets under administration by the group rose to £328bn at the end of June from £307bn at the end of December. Management was so impressed by these figures that they decided to increase the company's interim dividend by 7.5% to 6.5p.

Shares in Standard jumped by more than 5% after the company posted this impressive trading performance. But even after these recent gains, shares in the company still trade at a relatively attractive forward P/E of 12. The shares support a dividend yield of 6.2%.

Preparing for uncertainty

Legal's shares took a battering yesterday after management warned alongside first half results that the company wasn't immune to global uncertainty. However, in the same statement management expressed confidence in navigating through any Brexit-driven economic turbulence.

Aside from this warning the company's first half results were extremely impressive. Profit for the first half increased by 4% to £777m, annuity assets in the L&G Retirement business grew 18% year-on-year and assets under management at L&G Investment Management rose 18%.

Shares in Legal currently trade at a forward P/E of 10.3 and support an extremely attractive dividend yield of 6.7%.

Strong turnaround

Aviva proved the naysayers wrong when it reported a 13% increase in operating profit for the first six months of 2016 last week. After Aviva's £5.6bn acquisition of Friends Life last year, the company has been looking to prove to the market that the deal was a sensible acquisition. Last week's results seem to have allayed concerns for now with Aviva reporting that life insurance operating profit grew 20% in the first half, driven in the UK by synergies from the Friends Life merger. The value of new business in the life insurance arm increased 7% year-on-year and fund management operating profit rose 48% for the period.

Unfortunately, these strong performances were overshadowed by a 17% fall in profit at Aviva's General Insurance & Health division where underwriting profit was held back by the Flood Re levy in the UK.

Still, the strong overall group performance gave management the confidence to hike the company's interim dividend by 10%. Current City figures suggest Aviva's shares support a dividend yield of 5.5% and trade at a forward P/E of 8.7. The company's earnings per share are expected to grow by 99% this year to 44.9p.

The worst mistake you could make

According to a study conducted by financial research firm DALBAR, the average investor realised an average annual return of only 3.7% a year over the past three decades, underperforming the wider market by around 5.3% annually.

This underperformance can be traced back to several key mistakes that all investors make. To help you realise and understand the most common mis-steps, the Motley Fool has put together this new free report entitled The Worst Mistakes Investors Make.

The report is a collection of Foolish wisdom, which should help you avoid needlessly losing too many more profits. Click here to download your copy today.

Rupert Hargreaves owns shares of Standard Life. The Motley Fool UK has no position in any of the shares mentioned. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.