Only a handful of former Ethereum miners are able to survive in the post-Merge world, and some are making it by hopping from token to token. Those that are able to survive are eking out smaller profits than they enjoyed when they were mining ether.

In September, the Ethereum blockchain, built for smart contracts and decentralized applications, switched from a proof-of-work (PoW) consensus mechanism, which requires mining, to a proof-of-stake (PoS) model, which needs validators.

Dubbed “the Merge,” the change decreased Ethereum’s energy usage by 99.998%, thwarting a major criticism on blockchain networks, but it meant that thousands of miners had to figure out what to do with their equipment, a key source of income for many.

Over a month later, fewer than 20% of Ethereum miners, or 200 terahash (TH), a measure of computing power, “were able to find a new home in crypto mining, while also suffering from a significant decrease in margins,” said Ethan Vera, chief operations officer at mining services company Luxor.

Alternative coins, or altcoins, reward miners for their computational work significantly less than ether or bitcoin. That’s because their price tags are far lower than ether or bitcoin. Some miners have chosen not to mine at all after the Merge because they had already recouped their initial investment on graphics processing units (GPU) a while back.

As such, only those with the most efficient machines and lowest power costs can mine altcoins without finding themselves in negative margin territory.

Given the current market, altcoins can only accommodate about a fifth of the global hashrate and miners are faced with the fact that their mining revenue does not cover their electricity bills, a spokesperson for mining pool f2pool said.

But at the same time, as miners flock to mining any PoW token, a mechanism known as difficulty kicks in, meaning it is less likely for them to earn a reward, thus further lowering their earnings.

To take advantage of these quickly shifting winds where reward values change with token prices and the likelihood of earning rewards changes with the difficulty, publicly listed miner Hive Blockchain (HIVE) is using a switching algorithm that automatically redirects its GPUs to the most profitable coin, said Aydin Kilic, the firm’s president and chief operating officer. Hive then exchanges these coins into bitcoin.

Thus, its strategy overall is to repurpose and optimize its GPUs to expand its BTC production, the president said. That way, Hive earns more dollars per kilowatt-hour than by just mining ethereum classic (ETC) or ravencoin (RVN), Kilic said.

Similarly, miners flocked to the Nicehash platform because of its software that enables this type of automated switching in the 24 hours after the Merge, said Joe Downie, chief marketing officer at the hash power brokerage platform.

Downie said the platform went from about one million to 600,000 customers across Nicehash products after the Merge.

After the Merge, altcoins faced feedback loops of miners flooding a token, increasing its difficulty and then leaving the network.

The majority of miners mined right up to the last minute possible. While some were unsure what to do when the Merge took effect, many had already made plans, said Downie.

Larger miners prepared in advance, some even repurposing their GPUs for artificial intelligence and cloud computing, but many solo miners had to play it by ear.

After the network switched to PoS, miners behaved “frantically,” with “the vast majority hopping from coin to coin in attempts to remain as profitable as possible,” said a representative for mining software provider Hiveon. But this led to a “vicious cycle” in which miners saturated a market until they were forced to abandon it.

The Ethereum Classic blockchain’s hashrate jumped about fourfold from Sept. 12-16, around the time of the Merge, to around 200 terahash/second (TH/s), and its difficulty concurrently went up by about the same factor, data from CoinWarz shows. Ethereum Classic’s hashrate has since fallen to about 125-135 TH/s, as miners got priced out of mining the Ethereum fork.

Ethereum Classic is the easiest switch because its algorithm is the closest to mining Ethereum, Downie said. The blockchain was formed by a fork on Ethereum in 2016.

Similar trends were evident for mining ravencoin (RVN), beam (BEAM) and ergo (ERG).

Miners that use GPUs are mainly going for ravencoin, Downie said, as ETC is increasingly dominated by application-specific integrated circuits (ASIC), specialized computers like those used for bitcoin mining.

Much like the rest of the industry, Ethereum miners of the past are waiting for a bull market, keeping their machines humming in hopes other coins will pump in the future.

“Some miners still chose to continue mining even though their revenues could not cover electricity bills,” f2pool said.