There is time where price of ethereum going down and if it happen that is time for buy ethereum and hold. Don't missed for second time again.

I am doing some range trading at the moment. If it drops below 0.019, I will buy, if it is higher than 0.023, I will sell.

That is what i mean, so there are not missed train. Because price of ethereum is fluctuating.

Once the DAO is over, I think the price will go down.
Now will be a good time to do margin trading.

Do you mean borrow the Etheruem and sell short? The DAO can absorb 15 million Etheruem, it is better not to short.