(Bloomberg) -- Inscriptions are a type of nonfungible tokens that first took off earlier this year on the Bitcoin network. Now they are now popping up on more than a dozen other smaller blockchains, pushing up transaction fees and in some cases, bogging down networks. 

The stampede to mint the hybrid tokens is the latest speculative frenzy for seemingly all things crypto this year, from Bitcoin’s remarkable comeback to the eyepopping returns being realized on the most recent dog-themed memecoin on the Solana network. 

“It’s kind of like dog coins — people make a dog coin on each chain [because] other dog coins are popular,” said Zaheer Ebtikar, founder of crypto fund Split Capital.

Read: Dog-Themed Memecoin Jump Highlights Solana Recovery From FTX 

Unlike better-known NFT collections such as Bored Apes and CryptoPunks, which are created via software code on Ethereum and other blockchains, inscriptions are minted directly on the blockchain through a protocol called Ordinals. The transactions related to Ordinals and inscriptions on Bitcoin have surged again since November, according to Julio Moreno, head of research at crypto data firm CryptoQuant. 

“I think it’s good for the chain to have more demand,” said Leo Mizuhara, founder and CEO of DeFi institutional asset manager Hashnote. “In addition, the NFT-type of inscriptions data are actually fully written to the blockchain, unlike in Ethereum, so from a technical perspective, they have some benefits as well.”

It didn’t take long for some crypto fans to realize that they can also use the same method to mint NFTs on other blockchains. Data from Dune Analytics created by user @hildobby shows that there are more than 161 million inscriptions on Polygon PoS blockchain and 78 million inscriptions on Binance BNB Chain. As a result, inscriptions have also become a leading contributor to transaction expenses, or gas fees, on the blockchains that now are swamped with inscription-related transactions. 

“I kinda just see it as the new hot thing,” said Michael Rinko, an analyst at crypto research firm Delphi Digital. There is “zero rationality behind it.”    

When Ordinals became popular earlier this year, some members in the Bitcoin community also argued that the project would crowd out regular transactions with high fees due to the large amounts of data required to inscribe the digital images, and GIFs. That has become a problem on some of the other blockchains. Dune Analytics’ data shows that on the Avalanche blockchain, for example, users have spent as much as $5.6 million a day to create and move inscriptions. The Ordinals-inspired inscriptions also led to a temporary outage on Arbitrum, an Ethereum scaling project last week.

Rinko noted that the surge in activities also came with a lot of “spam” transactions since they are relatively cheaper than a NFT transaction via smart contracts, or pieces of code powered by the blockchains. Observers also point out there are few use cases of the inscriptions beyond speculation, especially compared with Bitcoin Ordinals.

“There aren’t many benefits over traditional tokens, just projects minting and speculating to chase the Bitcoin Ordinals narrative,” said Ben Yorke, vice president of ecosystem at exchange WOO. 

--With assistance from David Pan.

©2023 Bloomberg L.P.