Fixed mortgage rates in Canada don't move because the Bank of Canada raised its rate. They move because bond yields moved. Those are two different things, and confusing them leads to real mistakes when you're deciding whether to lock in, wait, or renew early.
Here's how it actually works.
The short version
When Government of Canada bond yields go up, fixed mortgage rates follow. When bond yields fall, fixed rates tend to fall too. The relationship isn't instant and it isn't 1:1, but it's consistent enough that bond yields are the single best leading indicator of where fixed mortgage rates are heading.
Variable mortgage rates work differently. They're tied to the Bank of Canada's overnight rate, which filters through your lender as the prime rate. Bond yields have almost no direct effect on variable rates.
Fixed rates follow bond yields. Variable rates follow the Bank of Canada. Two separate levers.
Why do lenders use bond yields to set fixed rates?
When a lender offers you a 5-year fixed mortgage, they're making a promise to lend you money at that rate for five years. To fund that loan, lenders borrow in the bond market, typically by issuing mortgage bonds or buying Government of Canada bonds as a benchmark.
The 5-year Government of Canada bond yield is the lender's baseline cost of funds. If that yield is 3.5%, the lender needs to charge you at least 3.5% plus a spread to cover their operating costs and profit margin. That spread has historically run between 1% and 2%, depending on competition, risk appetite, and market conditions.
So the formula looks roughly like this:
Your fixed rate = 5-year GoC bond yield + lender spread
Bond yields rise, your fixed rate rises. Bond yields fall, your fixed rate has room to fall.
What moves bond yields?
Bond yields are set by the market, not by any single institution. They move based on what investors collectively believe about the economy's future. The main drivers:
- Inflation expectations. Higher expected inflation pushes yields up because investors demand more return to compensate for purchasing power loss. Lower inflation brings yields down.
- Bank of Canada policy signals. If the BoC signals rate hikes ahead, bond yields often rise in anticipation. If the BoC is cutting or signaling cuts, yields tend to fall.
- Economic growth data. Strong GDP, low unemployment, and robust consumer spending push yields higher. A slowing economy tends to pull them down as investors move toward safer assets.
- Global events. U.S. Treasury yields, geopolitical uncertainty, and commodity prices all influence Canadian bond markets. Canada doesn't operate in isolation.
- Government borrowing. When governments issue more bonds to finance deficits, increased supply can push yields higher if demand doesn't keep pace.
The lag: why rates don't move the same day
Bond yields change every trading day. Fixed mortgage rates don't. Lenders don't reprice every time the 5-year yield ticks up or down by a few basis points. They watch the trend and move when yields have shifted enough to make repricing worthwhile.
Typically there's a lag of a few days to a few weeks between a significant yield move and a corresponding rate change at lenders. In a fast-moving market, yields can shift substantially before lenders post new rates. That lag cuts both ways: rates can stay high even after yields have started falling, and can stay low for a few days after yields have already spiked.
If you're watching bond yields as a timing signal for your renewal or purchase, look at the trend over 2 to 4 weeks, not daily moves. A single day's spike often reverses quickly. A sustained shift in one direction is what causes lenders to move.
Fixed vs variable: a side-by-side
| Rate Type | Driven By | Changes When |
|---|---|---|
| Fixed mortgage rate | 5-year Government of Canada bond yield | Bond yields shift meaningfully (days-to-weeks lag) |
| Variable mortgage rate | Bank of Canada overnight rate (via prime rate) | BoC announces a rate change (effective immediately) |
| HELOC rate | Prime rate | Same as variable: BoC announcement day |
What this means when you're renewing
When your renewal letter arrives, the rate your lender offers you is priced off where bond yields sit that week. It has nothing to do with the rate you got five years ago.
If yields have risen significantly since you last renewed, your new fixed rate will be higher regardless of your payment history, credit score, or loyalty to the lender. The lender isn't penalizing you. The market moved.
This is exactly why shopping your renewal matters. The spread a lender charges above the bond yield varies. Your current lender may offer Prime + 1.5% while a competing lender offers Prime + 1.1%. That 0.4% difference on a $500,000 mortgage is roughly $2,000 per year. Over a 5-year term, it's $10,000 before considering amortization effects, see how amortization changes the total using my mortgage comparison calculator.
Renewing in the next 6 months?
I'll pull current bond yield data and show you exactly what's available from lenders right now. Takes 30 minutes and costs nothing.
Book a Discovery CallShould you lock in when yields are rising?
This is the question most clients ask, and there's no universal answer. Here's how to think about it:
Locking in makes sense when: you have a tight budget and need payment certainty, yields are rising and the trend looks sustained, or you're planning to hold the property for the full term.
Staying variable makes sense when: the Bank of Canada is in a cutting cycle, you have financial flexibility to absorb payment changes, or you expect to sell or refinance before the term ends.
The honest answer: no one consistently beats the market on rate timing. Brokers who tell you they know exactly where rates are heading are guessing. The right call depends on your personal financial situation, not on rate predictions.
Common questions
Does the Bank of Canada control fixed mortgage rates?
Not directly. The Bank of Canada sets the overnight rate, which influences variable mortgage rates and prime rate. Fixed mortgage rates are driven by the bond market, which responds to BoC policy signals but operates independently. The BoC can raise its rate while fixed rates stay flat or even fall, if bond yields move in the opposite direction.
Why did my fixed rate go up when the Bank of Canada didn't change anything?
Because bond yields moved. Strong economic data, rising inflation expectations, or U.S. Treasury yield increases can all push Canadian bond yields higher without any action from the Bank of Canada. When yields rise, lenders reprice their fixed rates accordingly.
How much does the lender's spread affect my rate?
Significantly. Two lenders looking at the same bond yield can offer rates that differ by 0.25% to 0.75% depending on their cost structure, risk appetite, and how aggressively they're competing for new business. This is why getting multiple quotes through a broker matters. The bond yield is the same for everyone; the spread is not.
Where can I track the 5-year Government of Canada bond yield?
The Bank of Canada publishes daily bond yield data at bankofcanada.ca. You can also find it on most financial news platforms. The 5-year benchmark yield is the one to watch for fixed mortgage rate direction.
If yields are falling, should I wait before locking in a rate?
Possibly, but there's real risk in waiting. Rate holds from lenders protect you if rates go up during the hold period, but you still benefit if rates drop before you close. Waiting without a rate hold leaves you fully exposed. The better move in most cases is to secure a hold, then monitor whether lenders drop their posted rates before your closing date.
The bottom line
Bond yields drive fixed mortgage rates. The Bank of Canada drives variable rates. They're connected to the same economy but move for different reasons on different timelines.
Knowing the difference won't tell you exactly where rates are going. But it will help you ask better questions, avoid bad advice, and make decisions based on how mortgage pricing actually works, rather than on what the headlines say the BoC did last Tuesday.
If your renewal is coming up and you want to look at current bond yield levels alongside what lenders are actually offering, that's exactly what a broker is for.