I agree with Alan about the user segmentation of 90% speculation, 5% illegal trade, 5% legal trade. Thus a speculative crash seems quite likely. Bitcoins have even less intrinsic value than fiat currencies because as far as I can tell, there's not sticky pricing in bitcoins -- it's all pricing in fiat currency with an instantaneous numerical conversion to BTC. That is, there's nothing that 1 BTC will buy today that one can be reasonably confident that that 1 BTC will buy tomorrow. The more interesting issue, given all the noise around transaction malleability is whether the sum total of bitcoins that people think they own exceeds the sum total of bitcoins ever created. I don't think bitcoin is in the same boat as Lehman et al because there's (almost?) none of the nonlinear payoff instruments (e.g. CDS), leveraged amplification of losses, chaining of balance sheets (in which one entity's assets are another entity's liabilities and the second entity's assets are a third entity's liabilities, etc.), or transparency requirements (by which the reputations of entities may be damaged by required reporting of losses). As a medium of exchange, bitcoin is interesting but imperfect due to the messy blockchain transaction commitment process and under-resourced exchanges. As a store of value, bitcoin is utterly horrible due to extreme volatility, lack of sticky-price goods, regulatory risks, lack of transaction repudiation mechanisms, and the inability to recover stolen coins. An entity might choose to transact in bitcoins for a number of reasons but no sane non-speculative entity would hold bitcoins for very long.