Investors in high street fashion company Supergroup (LSE: SGP) received a boost today with the release of an encouraging Christmas trading update. Retail sales increased by 15% versus the prior year in the 11 weeks to 9 January, with a European store roll-out programme being a key reason behind the strong sales performance.

In fact, Supergroup opened 11 new stores across Europe and looking ahead, there appears to be considerable scope for more expansion outside of the UK over the medium term. Furthermore, Supergroup has maintained gross margin growth guidance for the full year of between 40 and 60 basis points which, given the unseasonably warm weather, is good news.

With the company being forecast to increase its bottom line by 15% in the current year and by a further 18% next year, it remains a relatively strong growth play. And with Supergroup’s shares trading on a price-to-earnings growth (PEG) ratio of just 1.2, they seem to offer upside potential – especially with European expansion and e-commerce progress being highly encouraging.

Good but not good enough

Also reporting today is cash and carry specialist Booker (LSE: BOK). Its shares have outperformed the FTSE 100 by a whopping 175% over the last five years and as such, many investors may feel it’s too late to buy a slice of the business. After all, Booker trades on a price-to-earnings (P/E) ratio of 22.7, which is over 50% higher than the FTSE 100’s rating.

However, today’s update from Booker shows that it’s making pleasing progress. Total sales in the 16 weeks to 1 January increased by 11% versus the same period of last year, with the recently acquired Londis and Budgens stores being successfully integrated into the business. Like-for-like (LFL) sales, though, fell by 3.1% as Booker suffered from food price deflation as well as weaker consumer demand. Looking ahead, more pain in this space could be on the cards. As such, Booker doesn’t appear to be an appealing buy.

Long-term appeal

Like Booker, Aviva’s (LSE: AV) share price has performed well in recent years, with it being up by 25% since the start of 2013. A key reason for this is the life insurer’s successful turnaround strategy that has allowed it to move from being a lossmaking entity in 2012 to being forecast to deliver earnings per share of 44.6p for the 2015 financial year.

But Aviva’s turnaround isn’t yet complete. It still needs to integrate the recently-acquired Friends Life business and in doing so is expected to generate significant synergies that should make the combined entity a highly efficient and dominant life insurer. With Aviva trading on a P/E ratio of 10.6 and being forecast to increase its bottom line by 11% next year, it doesn’t appear to be too late to buy a slice of it. For long-term investors, Aviva remains one of the most appealing financial stocks in the FTSE 350.

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Peter Stephens owns shares of Aviva. The Motley Fool UK has recommended Booker. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.