Current interest rates are available daily. If rates increase, many buyers are forced out of the marketplace. With fewer buyers in the marketplace, the chances of finding a buyer willing to pay your price decreases. You can't predict what's going to happen with interest rates. Nobody can. There is an advantage in dealing with a known set of circumstances.
For example, let's say you're selling a $100,000 property and looking to buy a $150,000 property. If both properties appreciate at the same rate of 3% over the next six months, you gain $3,000 on your existing property. However, the $150,000 property will now cost you $154,500 or a net loss of $1,500. Also consider the situation where the market is in fact a depreciating market. Now the house you own may in fact be worth less 6 months from now but the more expensive home you want to buy will be worth less also but here you will gain more than you lose on the current house you own.
Here is an example: You own a $200,000 home today. In 6 months it may be worth only $180,000. You want to buy a house worth $300,000 now but in 6 months using the same percentage depreciation, it would be worth only $270,000. So you lose $20,000 on your house but you gain $30,000 on the trade up house. In a depreciating market such as we have now, the possibility of gaining when you trade up is very real. Savvy buyers and sellers have recognized that and are in the market!
By waiting, many sellers have put themselves in a "have to sell" situation and ended up having to accept an offer for less than what they wanted. The fact is when you have time on your side, you won't feel pressured to accept an offer that's less than what you want.
However in a depreciating market, what the market says your home is worth today may actually be more than what the market says it is worth in 6 months.
We are currently dealing with a known set of circumstances. There is no guarantee that in a few weeks, or a few months, there might be fewer buyers, or more sellers in the marketplace. Either way, by waiting you are taking a gamble with accomplishing your real estate objectives.
Should the federal government decide to change capital gains or interest deductions, you could risk the current tax advantages which we currently enjoy.
If you knew that waiting might cost you a significant chunk of money, would you still want to wait? Part of the reason you hire a professional is to provide you with all the facts so you can make an informed decision.