We take the long view with our stock picks. It’s a mistake to react to every piece of news or price fluctuation. Impulsive decisions lose money.

But portfolios aren’t static. That’s especially true when it comes to the innovators in the Breakthrough Tech Profits portfolio. When meaningful developments occur, we must act decisively.

Here’s what you need to know now.

• BioTelemetry (NSDQ: BEAT)

Apple (NSDQ: AAPL) this month launched a new Apple Heart Study with Stanford University Medical Center. The main technology partner is BioTelemetry.

This study will use a new Apple Health Study app with Apple’s Watch. The goal is to monitor heart problems in patients. BioTelemetry’s cardiac devices play the central role.

This study could pave the way for huge demand for BioTelemtry’s products. If Apple decides to include BEAT’s devices in its products, the payoff could be vast. BioTelemetry already gains by aligning itself with the Apple brand. I’ll keep an eye on the study.

BEAT’s buy limit remains $37.

• Cognex (NSDQ: CGNX)

Manufacturing activity is rebounding around the world. That’s a tailwind for machine vision firm Cognex.

Cognex’s products analyze visual data to automate factories. With a market cap of $10.9 billion, the company occupies the “sweet spot.” As a mid-cap, it’s less risky than the small fry. But it’s small enough to offer more growth potential than its large rivals.

Analysts estimate that CGNX’s year-over-year earnings growth will come in at 59% this year year. I expect the firm to generate five-year earnings growth of 24% on an annualized basis.

Cognex executed a 2-for-1 stock split, effective December 4. When a company splits its shares, the market cap stays the same. That means you own more shares but each are valued at a lower price per share. A key goal is to attract a wider range of buyers. Cognex’s stock split is a bullish sign, but it compels me to adjust the buy limit.

I’m lowering the buy limit on Cognex from $145 to $80.

• Evolent Health (NYSE: EVH)

Evolent on December 8 announced it was terminating its arrangement to buy Premier Health Plan.

Health plan administrator Evolent wanted Premier’s four hospitals. The idea was to create an integrated network with economies of scale. But the two parties couldn’t reach terms.

Premier and Evolent have been partners for a long time. Their operations already are integrated. This won’t change. EVH’s managed care services continue to grow as health care demand booms. EVH’s Medicare segment is particularly valuable.

Evolent’s buy limit stays at $26.

• Himax Technologies (NSDQ: HIMX)

Short sellers are trying to make a quick buck from HIMX. In a tweet on December 6, Citron Research stated:

“Looks like market starting to realize the bull*** story behind $HIMX and who is counting the beans – mgmt history of fraud will always haunt this promo.”

Since the tweet, HIMX shares have tumbled 17%. That was predictable.

On December 8, Himax responded. The key quote in HIMX’s press release:

“The Company reaffirms its commitment to transparent and reliable shareholder communication, and its adherence to the highest standards of corporate governance. Himax cautions investors that Citron Research has never made any contacts with the Company and that the tweet did not contain any input from the Company. Himax categorically denies any and all allegations of fraud.” 

Citron is a blog with no accountability. Citron has a history of publishing critical reports on companies without evidence. In the case of Himax, Citron provided no evidence of its accusations. Even when pressed, Citron provided no details.

My view: Citron slandered HIMX, allowing short sellers to pile on. Himax has had a great run this year. I’d like to thank Citron for handing my readers a buying opportunity.

HIMX’s buy limit stays at $20.

• Western Digital (NSDQ: WDC)

Morgan Stanley (NYSE: MS) last week issued a report that warned about semiconductor stocks. Western Digital was included. The report stated:

“We think now is the time to reduce exposure to NAND [flash memory] and Asian semiconductor names as the industry has benefited from sizeable demand tailwinds and unprecedented pricing power, which we see reversing soon.” 

The report hurt chip makers across the board. Chip makers might face slowing demand, but it’s stupid to punish all chip stocks. You should always resist the herd mentality.

The fact is, WDC is a value. WDC’s forward price-to-earnings ratio is 6.72, which is reasonable in light of the company’s growth prospects. Overbought chip makers are vulnerable. Not Western Digital.

WDC should get a boost from the resolution of its dispute with Toshiba (OTC: TOSBF). On December 7, the two companies agreed to settle. They’ll announce the details next week.

Western Digital will end arbitration claims to stop Toshiba from selling its chip business. In return, WDC will get an extension of their joint venture.

The upshot: WDC will get a steady supply of advanced chips. That’s a coup for WDC.

WDC remains a buy up to $103.

John Persinos is chief investment strategist of Breakthrough Tech Profits.