Stock price when the opinion was issued
Now paying 15-20 bps higher than a plain-vanilla high-interest savings ETF. Good if you need access to cash, never drops below where you bought it if you buy on the ex-dividend date. A cash-like position in your portfolio. Pays interest.
The sawtooth graph is explained as money accumulating on short-term paper holdings, and then paid out all at once every month. You can, of course, automatically reinvest the proceeds.
Money market exposure, but focused on government debt. Both buy instruments of less than a year's duration.
ZST is corporate debt -- slightly higher risk, so you get a premium yield. No junk bonds. Best-quality corporate bonds in Canada. Some credit risk, but quality holdings make this minimal. Money-market like, very safe, additional yield. Likes it.
When he compares these two, it's on total return not just the yield. If you look at the price charts of these 2 ETFs over the last few years, you'll notice that in this falling rate environment the money market securities have a very slight downward trend in terms of their average price. Whereas ZST and its corporate bonds have a very slight upward trajectory, owing to their slightly longer duration.
When you look at the coupon payments, largely what's in ZMMK is commercial paper. While that's corporate credit, Canadian government bills and so on, there's still overall an aggregate yield that's less than what you're getting on a total return basis.
A lot of the bonds under a year that are being purchased in ZST are being purchased at a discount. So you get the coupon plus a little bit of capital growth. Total return is not a lot more, but still more.
ZMMK and ZST are his two favourite BMO ETFs for money market exposure. He uses both in the bond fund he manages. Which one you chose depends on your risk tolerance. Both are excellent, look at both.