Bitcoin (BTC) now has the highest share of the overall cryptocurrency market since before its record-breaking $20,000 bull run in 2017.

According to data from major monitoring resource CoinMarketCap, Bitcoin now accounts for 70.5% of the total cryptocurrency market cap as of Sept. 3.

Bitcoin market cap hits pre-$20K high

That figure has not been seen since March 2017, and comes as BTC/USD makes gains at altcoins’ expense.

As Cointelegraph reported, continued underperformance in cryptocurrencies other than Bitcoin has triggered warnings from traders and analysts alike.

Among them are Peter Brandt and RT host Max Keiser, the latter again claiming this week that altcoins would never recover from this downturn.

“Alts never coming back… Sorry,” he tweeted on Sept. 3, also referencing market cap statistics. Brandt reiterated similar warnings.

“When will altcoin junkies understand that $BTC is the crypto with real and lasting value,” wrote Brandt, who added:

“Altcoins are to Bitcoin what lead is to Gold.”

Some sources had reported Bitcoin hitting the 70% mark as early as last week.

Market cap readings set highs across the board

Bitcoin itself delivered a sudden return to form late on Monday, having previously dropped to just $9,350. At press time Tuesday, BTC/USD was circling $10,360, bringing 24-hour gains to 6.2%.

Altcoins in the top twenty, however, mostly failed to achieve more than 4%, meaning they, in fact, lost value in Bitcoin terms.

Some commentators voiced caution about placing faith in Bitcoin’s strength. Market cap, they argued, is a poor measure of performance, as it includes many altcoins which do not even have any trading volume.

Earlier, Cointelegraph reported on the phenomenon of Realized Market Cap, a metric designed to solve those inconsistencies which has also set new records in recent weeks.