Among famous cryptos, week-to-date, BTC has fallen by 6%, DOGE by 7%, NXT by 13%, Stellar by 16%, Mastercoin by 25%, and BTSX by 35%... Thus please don't forget the whole space is currently in a rather bearish environment, and given the recent uncertaintly and upcoming changes for BitShares one should expect BTSX to underperform.
The % loss might resemble a bubble/bust one observes in a broad stock market. Having said that, losing 2/3 of $ value from the top (less so in market cap terms) is way too small compare to crashes in individual technology stocks/sectors. Even BTC lost 4/5 from the respective tops during two recent downturns, not to mention pump-and-dumps previously observed in cryptos.
Given the amount of uncertainty/perceived risk for the whole crypto space and crack-downs by regulators, there was little new institutional or mass retail money inflows coming into the sector following the liquidation of rather speculative positions in Dec 2013... The whole crypto economy is currently struggling with the negation of super optimistic price and adoption predictions by BTC evangelists last year.
So for BitShares community, it is a good time to stay patient in terms of price expectations and concentrate on productive work, consolidating internal strength and planting the seeds of future success.
Most of the POW-altcoins medium-term survival depends on speedy adoption, on a successfully launched rocket (like DOGE). Otherwise there is no reason to stay invested, because there is no substance for the "secondary rocket" to take off when such coin's very functionality is compromised or descending into insignificance among 500 competitors... In such projects the slogan "HODL" is spread by pumpers into the believers in order to enable them to offload maximum worthless coins at elevated prices.
BitShares as a project is in a very different position with committed developers and marketers, superior tech, strong business ideas, bright community, and secured startup funding. So, however difficult it might be watching negative "mark-to-market", there is neither reason to panic, nor to follow frequent price movements too closely and emotionally (every down move usually creates 3 x negative emotional energy compared with positive from a correspondent upmove, unless you are waiting to buy cheap). Even if sales by weak hands and good traders caused the market cap to fall further in the region of $10m, apart from emotional reactions by HODLers this doesn't provide new reasons to doubt the medium-term push and long-term perspective. Therefore, I suggest that the main reasons for HODLing BitShares are both committment to the project and the uncertainty of when / at what level exactly the price bottom is completed and turn-around occurs (usually at time of widespread pessimism and following bad news). Dedicated investors can at any time follow their own educated guess with regards to the probability of complete failure, thus adjusting the size of their BTS stake whenever they see significant chance of failure.
On that note, I wish everyone sincerely involved into BitShares patience and strong moral, leading to amazing success in the (even maybe if not immediate) future!