Here's What Bitcoin's Smartest Skeptics are Telling Investors.

Bitcoin continues one of the most dramatic price runups of any asset in living memory, posting prices above $11,800 this morning after starting the year below $1,000 per digital token. In its early years, skeptics with little knowledge of blockchain technology were quick to dismiss Bitcoin as a fleeting trend. But as knowledge spreads and prices chase new highs, the skeptics have become more nuanced – and even if you love Bitcoin, they’re often worth listening to.

Here are a few of the most notable bear sentiments being aired as Bitcoin’s rip-roaring rampage continues.

Blockchain without Bitcoin?

At last week’s Consensus: Invest conference in Manhattan, some of the greatest minds in asset management came together to talk @cryptocurrency. On a “Bulls and Bears” panel, Raoul Pal of the Real Vision financial news network repeated a favorite saw of today’s more informed bears – that while blockchain database security is a revolutionary technology, those blockchains will ultimately be privately managed by enterprises. That would eventually drive the value of public @blockchains like @Bitcoin to zero.

But the idea of a private blockchain at least partly misunderstands the core security premise of the technology. Cryptocurrency payouts attract a decentralized swarm of hosts who ensure the honesty of a shared ledger, without necessarily having a stake in its contents. Andreas Antonopoulos, long one of the smartest commentators in the space, has dismissed private blockchains as a fundamentally inefficient replacement for an old-fashioned database. Once real-world blockchain applications are up and running, most will likely be hosted on one of the trusted public blockchains, such as Bitcoin or @Ethereum.