Should you buy these FTSE surgers and sliders?

Shares in Nanoco(LSE: NANO) have taken a pummelling in Tuesday trade, the stock last 10% lower after releasing a less-than-appetising trading update.

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The quantum dot specialist advised that full-year revenues for the period to July 2016 slipped 77% to £470,000, a result that caused pre-tax losses to widen to £12.6m from £10.88m a year earlier.

This is the second hefty share price fall in less than seven days, Nanoco advising last week that it had deferred licence fee royalties, with £500,000 to be booked for the year to July 2017 and £700,000 over the following six years.

Regardless of these roadblocks, Nanoco remains confident that its transformed business model should deliver stunning sales growth in the years ahead. The company has inked major contract agreements with the likes of Merck and Wah Hong in recent months, for example, assisted by its terrific record of innovation -- Nanoco's IP portfolio consisted of 467 patents and patents pending as of July 2016.

And the Mancunian business has stepped up manufacturing capacity to speed up returns from its cutting-edge technology.

These measures should push Nanoco into the black from this year, at least according to City forecasts, and earnings of 1.3p per share are currently forecast.

Value hunters will no doubt be put off by a subsequent P/E rating of 41.9 times, soaring above the benchmark of 15 times broadly considered reasonable value. Still, those seeking stocks with potentially-explosive long-term earnings potential could do a lot worse than to check out Nanoco.

Too soon?

Victrex (LSE: VCT) has enjoyed a more pleasant ride so far in Tuesday's session, with a mostly-positive trading update pushing investor demand up 7% from last night's close. The polymer manufacturer is now dealing at fresh 10-month peaks.

But first the bad news. Victrex said that total revenues slipped 4% to £252.3m in the 12 months to September 2016, with declining demand at its Consumer Electronics unit pressing down on the top line. Yet Victrex has suggested that things are starting to look up, the company advising of "an improved performance in the second half and a good finish to 2016."

Critically the business has seen conditions stabilise in the Oil & Gas division, it noted, while its Aerospace and Automotive arms have also been "performing well." And volumes at Consumer Electronics more than doubled during April-September from the previous six months.

But investors should refrain from breaking out the bunting just yet, Victrex warning that "our early planning assumption suggests Consumer Electronics volumes will be significantly lower in 2017." And of course demand from the fossil fuel sector could also deteriorate again should pressure on oil producers' capex budgets persist.

The City expects Victrex to register a 7% earnings bounce in fiscal 2017, resulting in a P/E rating of 18.6 times. Considering that the firm's core operations aren't quite out of the woods, I reckon cautious investors should sit on the sidelines for the time being.

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