Ok, so when you use those water bongs (legally, of course, in California and quite a few other states), there’s usually a line (so we are told) that happens to etch onto the glass inside of the bong if the water gets so nuked from gnarly bud that it greens.
Um. Ok, so yeah...that is one definition of high water mark, but...don’t bring it up with your portfolio manager boss.
The HWM you probably care about is the high a stock made.
Like…whatever.com (WHAT) was doing great, selling little baby whatevers, and it’s stock lived around $55 a while, then trundled to $57, then $58…and got as high one day (see, that kind of high) as $58.27.
But that was it. The next day, whatever.com released news of their lousy quarter, and the stock has never been the same, passing $45 only rarely on any given trading day. Its high water mark was $58.27. So, uh...put that in your bong and smoke it (but check your state laws first).