Why btd /sbd/steem coin go down

As you can see in the last few days, there is a massive drop of these coins from different factors. It is best time to buy Steem and SBD because they are potentially huge at this point and will grow rapidly in the near future.
Bitcoin-After a massive run in 2017, cryptocurrencies have fallen sharply to the start of the year due to regulatory uncertainty. South Korean, Japanese and U.S. authorities have stepped up their scrutiny of cryptocurrency trading over the past few months.
SBD / Steem-why down?
One explanation that comes to me is that the price changes reflect the supply and demand for a particular currency. When prices go up - there are more buyers than sellers, when he went down - there are more sellers then buyers.
Do not be afraid of this little fall. The 3 will have a run very soon and will again reach 10k $ btc in a maximum of one month, and sbd and $ 5 $. Buying is the best time to do that.
Good luck