What causes prices to go up?
There are some specific things that cause market price to go up which block halving is one of the thing, market manipulation, good news, influential person or company accumulation, mining diffculty, level of market demand and supply.
What causes them to go down?
market manipulation (though it help in price increase but it also use to cause dump in price either), fud news, influential person or company exit, mining diffculty, level of market demand and supply.
Obviously, no one knows for certain when it would happened, but has there been a consistent "pattern" lately? When prices have gone down, have you known to a reasonable degree than they would bounce back up? How?
We can tell when it will happen but the market will bounce back up when it reaches the resistance level though we seem to currently be in altcoin season.