"Is their recent rally just the greater fool theory writ large, where you buy them today, confident that someone will pay even more for them tomorrow simply because they've got momentum?" the "Mad Money" host asked. "In this particular case, I think the answer is an emphatic no. The truth is that these companies are constantly innovating, always giving you new earnings-additive reasons to buy their stocks."
Cramer pointed to Thursday morning's news that Facebook would launch a subscription-based news service, working with various media outlets to aggregate content for its users.
"These are all new earnings per share boosters that give you more reason to buy the darned stock," Cramer said.
"Sears, its pathetic partner, doesn't have that much left, but it does have one of the best brand names in appliances. They haven't savaged that. Kenmore's still good. You put Kenmore together with Amazon, you throw in Alexa so you can scream at your washing machine all you want to turn on, and voila, you're off to the races," Cramer said.
Fresh off of an unexpectedly strong earnings beat, Netflix created buzz and likely boosted international subscriber numbers with its recently released film "Okja," a star-studded picture by famed South Korean director Bong Joon-ho about a giant, genetically engineered pig.
"Okja was Netflix's final release of the second quarter and I think it's the film that put international sign-ups over the top of domestics," Cramer said. "Right story, right publicity, fabulous knowledge of South Korean culture, all things that the conventional studios reject or just don't even know how to do."
Alphabet's Google also announced the roll-out of a new function on Wednesday that will personalize its mobile news feed to "keep you in the know even when you're not searching" and provide more "bite-size answers" to users' searches, according to a Google search executive.
"Now, I'm not saying these stocks can't go down — Alphabet and Netflix both declined [Thursday]," Cramer said. "I'm saying that they just keep making news, generating actual events and products that are indeed additive to earnings. Raising-numbers FANG. As long as that continues to happen, these stocks can continue to go higher, and you shouldn't feel foolish for pulling the trigger because they seem to introduce needle movers every single day of the week."
Disclosure: Cramer's charitable trust owns shares in Facebook and Alphabet. Additionally, CNBC parent NBCUniversal is an investor in Snap.