Just like almost all other coins, Steem has entered a phase of cooldown after an impressive peak last June. Although the decline of value and market cap looks rather severe, there is certainly no need to panic.
Let's look at the chart below; the market cap of Steem soared to over $600 million in June, but has decreased to somewhat over $200 million at this moment. The value reached almost $3 roughly a month ago, but has decreased to 'just' $1 nowadays. Compared to the absolute peak, it appears Steem has suffered staggering losses. However, in the extreme volatile market of cryptocurrencies it is never a good idea to compare values and market caps and whatnot to any peak, as it almost always makes the situation seem worse than it actually is.
Now, let's look at the chart with a greater timespan; notice how the graph suddenly appears a lot more positive; at the current value and market cap, Steem has still made gigantic progress compared to the first days of january 2017. This whole thing is actually quite representative of cryptocurrency as a whole; things should be viewed on a larger scale, as it becomes more appearant that the general trend is upwards with the usual ups and downs. We've just experienced an 'up' while we're now entering a period of 'down'. My guess? Steem - along with a whole bunch of other coins - is still in its infancy ... !