Times of economic difficulty tend to bring up talk of "safety stocks," but in times of economic prosperity, CNBC's Jim Cramer sees that narrative flip.

"What if the definition of safety is changing right before our eyes? What happens when what's prudent suddenly becomes what's reckless and what used to be reckless becomes responsible?" the "Mad Money " host asked. "That, gentle viewer, is exactly what we are seeing in this market."

With strong economic activity around the world, Cramer said investing standards are changing. In this kind of "synchronized economic expansion," stocks that may be seen as risky in other times could gain serious traction, he said.

One such stock is 3M, which delivered a handy earnings beat on Tuesday rife with orders from around the world.

"You could argue 3M's having one of its strongest years ever and that's saying something. This company was founded in 1902," Cramer said. "I am dazzled by the performance of this company and its stock, which soared from $220 to $237 in two days. This is a big, old-line industrial. You know what? It went down a little today. Pullback: gift."

Competitors trying to take a bite out of GrubHub's market share haven't been having much luck, GrubHub CEO Matt Maloney told CNBC on Thursday.

Maloney said that competitors like Postmates and Uber Eats, along with their venture-capital backers, have "wasted" billions of dollars on promotions in fruitless attempts to steal diners from GrubHub, currently the largest online food delivery platform in the United States.

"They've thrown it away, and then they pull back from the markets because you know what? It's not about the promos," Maloney told Cramer. "People want to connect with their restaurants. It's about the service. And the only thing we do is we connect diners to their restaurants."

Cramer has been noticing some disconcerting activity on social media as earnings season continues to drive the rally.

"I want to shine a light on something I saw in my feed on Twitter, something that's actually not a good sign ... for this red-hot, scorching bull market," he said. "It concerns me, and I want it to concern you."

Cramer had criticized AMD for losing steam after its quarter and sending ripples of worry across a variety of tech-related market sectors. But he didn't like the response he received.

"I went and looked at my feed today and what did I see? A very sizable number of AMD followers criticizing me for being short AMD and trying to blast it down with negatives," Cramer said. "This is called 'homer' behavior, raw home-team booster-ism that lacks any sort of objectivity or rigor and has no place in the stock market. This is how you lose money, people."

Nick Akins, the chairman, president and CEO of American Electric Power, told CNBC on Thursday that an economic uptick in the United States will be especially advantageous for his utility giant.

"When you look at the fundamentals of the economy right now, what we're really heartened about is we're seeing advances in all sectors of the economy. So not just oil and gas, but across primary metals. Even mining is coming back somewhat," Akins told Cramer. "It's really positive going forward."

American Electric Power, which owns a host of subsidiaries related to energy and electric utility, has also been investing in renewable forms of energy like wind as it develops its infrastructure, the CEO said.

"There's a lot of greenfield projects when it comes to renewables and other forms of energy. Not so much particularly in the nuclear or coal side of things," Akins said. "It's a huge amount of new investment [in] infrastructure and the capital deployed is really working out well for our shareholders."

The robot-ization at manufacturing giants has spurred a new conversation about labor, Briggs & Stratton Chairman and CEO Todd Teske told CNBC on Thursday in an interview with Cramer.

Briggs & Stratton, which makes hardware like small engines, power generators and lawn mower parts, has turned to robots for a large part of its manufacturing processes, the CEO said.

"Over the last few years, it's really been all about automation, and so we have more robots in one manufacturing cell than we had in the whole company when I joined 21 years ago," Teske said.

But for a company that has long tried to maintain a balance between capital and labor costs, Teske said the rise of robots has presented a new challenge.

"Ultimately, you get into skilled labor issues," Teske told Cramer. "And so you need people that can program and run the robots and maintain the robots and so what we've been focused on is how do we train up our people to be able to use a lot of this automation and this innovation that we're bringing to the shop floor so that we can remain competitive here in the U.S."

In Cramer's lightning round, he zipped through his take on some callers' favorite stocks:

Albemarle Corporation: "Oh, man. You cut me to the quick. I like right here a little bit more than Albemarle. Albemarle's stalled right now. "

Zagg Inc.: "Like Zagg. Buy, buy, buy, buy, buy!"