Author Bio Industrial sector focus. I write about electrical equipment, transportation, and multi-industry industrial stocks. Engineer, investment manager and property developer. I'm a firm believer that there is something noble about the industrial sector. Blue collar workers physically making a better world. Follow me on Twitter to receive quick and thorough analysis of your favorite stocks. Follow @LeeSamaha Ark Invest is known for its focus on investing in disruptive technologies, and industrial software company PTC (NASDAQ:PTC) certainly fits the description. The stock is one of the top 10 positions in ARK's 3D Printing ETF (NYSEMKT:PRNT) largely due to its computer-aided design (CAD) software. However, there's a whole lot more to like about the company, not least its exposure to the so-called fourth industrial revolution, or Industry 4.0. Let's take a look at what that is and why PTC is such an attractive stock for investors.