The Bitcoin Rich List, or the number of addresses holding more than 1,000 BTC, has grown in the past 12 months, possibly reflecting an influx of high-net-worth investors.

The metric has registered growth of 30 percent since September 2018, according to Coin Metrics data. Even when adjusted to exclude addresses known to belong to exchanges, the figure shows a similar surge.

At press time, 2,148 addresses contain more than 1,000 bitcoins, amounting to just 0.01 percent of all bitcoin addresses, as per BitInfoCharts’ Bitcoin Rich List.

As seen in the fever line chart above, the list has witnessed a near 90-degree rise over the last 12 months. Investor and analyst Willy Woo believes the list has expanded mainly due to increased investor participation in the market:

“The two options are we have high-net-worth investors coming in or it could be cold storage practice at the exchanges and custody solutions. The latter explanation cannot be ruled out, but it does not coincide with other data we have on the timing of when supply increased at these entities. For now, I’m going with the first explanation.”

Note that BTC fell from $6,400 to $3,100 in the final quarter of 2018 and experienced investors may have taken advantage of the price dip to snap up the top cryptocurrency on the cheap, leading to the rise in the addresses with more than 1,000 bitcoins.

Other observers, however, are not convinced that the number of individuals with 1,000+ BTCs has increased.

After all, an individual can move 50,000 bitcoins from a single wallet to 50 different wallets for custody purposes. Also, a cryptocurrency exchange like Binance holds bitcoins belonging to millions of users and can store coins in different wallets.

“It’s mostly the exchanges … both the amount of BTC held in exchanges and the number of exchanges/custodians have been growing,” trader Alex Kruger told CoinDesk.

He noted that on-chain transaction volume in BTC terms has been relatively flat since September 2018 – a sign the rich list is possibly increasing due to exchanges, which tend to have low on-chain transaction frequency. For instance, top addresses have fewer withdrawals compared to deposits and could, therefore, be exchanges’ cold, or offline wallets.

While trading volume is the lifeblood of exchanges, it is not necessarily reflected on-chain, since these companies may internally debit or credit client addresses without executing a transaction on the public ledger.

That said, it is not possible to know for sure whether a given address with infrequent transactions is an exchange or a whale.

Further, as shown in the chart below, if you take out known exchange addresses, the rich list still grew by almost 30 percent over the 12-month period, to more than 2,100 addresses, pretty much the same rate as for all addresses.

This supports Woo’s interpretation that the influx of high-net-worth individuals was a primary reason for the rise in addresses with more than 1,000 bitcoins.

One more possible reason for the rise could be the distribution of ownership over time, according to Qiao Wang, director of product at crypto data source Messari.

“In the beginning it was Satoshi, then a few early miners, who owned all the bitcoin. But over time their share decreased and other people entered the market,” Wang said.

Looking forward, both wealthy investors and exchanges may continue to drive the rise in the number of “rich” addresses. With the next mining reward halving – a historically price-bullish event – due in six months, new investors may enter the market.

Also, trading volumes at the Bakkt bitcoin futures exchange, which needs to store bitcoin for its physically delivered futures, are increasing. Recently, futures volume jumped by more than 250 percent to $11 million. The exchange, a subsidiary of Intercontinental Exchange, is set to launch options on futures on Dec. 8.

Disclosure: The author holds no cryptocurrency assets at the time of writing.

Champagne glasses image via Shutterstock; exchange-adjusted chart via Glassnode