Today I am discussing what I consider to be two blue-chip growth superstars.

Mobile marvel

The explosion in demand for smartphones, tablets and similar devices in recent years has seen ARM Holdings (LSE: ARM) emerge as one of the FTSE 100‘s most impressive growth selections.

The Cambridge-headquartered business has seen the bottom line expand at a compound annual growth rate of 17.3% during the past five years alone. Still, many fear that slowing phone and tablet sales could weigh on ARM’s earnings performance looking ahead.

These concerns certainly merit serious attention. Research house Gartner estimated this month that global smartphone device sales will grow just 7% in 2016, decelerating rapidly from the 14.4% rise registered last year.

However, these projections do not tell the true story. Sure, ARM may derive the lion’s share of its profits from the mobile device market. But the company’s cutting-edge hardware — such as its new ARMv8-A technology — is enabling it to grab custom from its major rivals, and makes it a firm favourite with industry leviathans such as Apple.

On top of this, ARM is rapidly diversifying into other tech segments, like servers and networking, to offset expected declines in its core mobile device market. Indeed, this drive enabled the business to ink 51 new processor licences during October-December alone.

Given these factors the City expects ARM to enjoy earnings growth of 43% and 13% in 2016 and 2017 respectively. While these figures may produce elevated P/E ratios of 29.1 times and 25.6 times respectively, I reckon the ARM’s rising expertise across a range of hot growth markets merits such a premium.

A medicines master

The pharmaceuticals sector is also a great place for growth hunters to go stock shopping, in my opinion, with  a backcloth of rising global populations and increasing healthcare spend the world over lighting a fire under medicines demand.

With this in mind I reckon AstraZeneca (LSE: AZN) could prove to be a very-lucrative growth pick for long-term investors.

The last five years has hardly been a cakewalk for the London-based business, the steady progress of generic entrants smashing the sales power of key labels like Crestor, Nexium and Seroquel XR.

Still, I believe the tide is turning as AstraZeneca ploughs the cash into its R&D operations to rejuvenate its product pipeline, particularly as the firm centres on rapidly-rising growth markets like oncology, diabetes and respiratory.

The City expects AstraZeneca to endure further earnings woes in the more immediate term, however, the business anticipated to follow a 7% decline in 2016 with a marginal drop next year. But with these figures leaving the drugs ace of just 14 times for these years, I reckon now is a great time to latch onto AstraZeneca’s rapidly-improving profits outlook.

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