For the 5th week in a row, institutional investors have increased their crypto holdings.

Cryptocurrency assets held by institutional managers rose for a fifth consecutive week, a sign that market participants had once again flipped bullish on Bitcoin (BTC) and the leading altcoins.

Investment flows into crypto products totaled $42 million in the week ending on Sept. 19, with Bitcoin funds seeing inflows of $15 million, according to digital asset manager CoinShares. That’s only the third time in 16 weeks that BTC investment products saw positive inflows.

All major assets registered a weekly increase, with investors buying up $6.6 million worth of Ether (ETH) products and $3.7 million worth of multi-asset funds. Investors also allocated $4.8 million towards Solana (SOL), disregarding a denial-of-service disruption earlier this week as a result of network congestion.

In terms of actual products, 21Shares registered the largest weekly inflows at $28 million. The physically-backed crypto exchange-traded product provider now has $1.87 billion in assets under management. Grayscale remains the single largest crypto asset manager, with $43.177 billion in total assets.

Fund managers have been buying up crypto in lockstep with a broad market recovery that began in late July. Crypto markets peaked above $2.2 trillion last week after plunging to around half that amount earlier in mid-July. However, by Monday, all major crypto assets had printed heavy losses as Chinese Evergrande news walloped risk sentiment.

Related: Bitcoin bounce levels extend to $36K with bulls unmoved by 8% BTC price dip

Institutional investors have become important players in the cryptocurrency market, which is a testament to the growing mainstream acceptance of digital assets.