Many thanks for your quick response.  Grayscale and ETC look very attractive right now.  Unfortunately, they are not offered by my broker.  They only offer XBT.
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Those two products are offered by Coinshares. As you noted, the only difference is the currency used for the NAV computations. If you want to protect yourself against of the EURO you should invest in the dollar one. But ultimately it is not a big issue, as a crumbling Euro would send the BTCEUR cross on the moon, without much effect on the BTCUSD. You might invest in the USD one just to avoid redenomination risk (in case of an EUR breakup).