Sorry, didn't answer your question.... working on something else too, so a bit distracted here

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Why the knock on GROW? I think it's the bear action myself. If the markets go in the dumper, and we go into recession, people will be bailing from stocks period.
The vast majority of people are holding funds, not individual stocks. Pensions, financial managers, analysts, etc all recommend funds... it's just easier for most people.
GROW has 4 and 5 star funds, but because GROW has less track record, people watch them more closely. Vanguard, Templeton, Fidelity, et al are so well established, people don't run to get their money out when the market crashes, they just complain around the water cooler.
They would sell funds like GROW has first.
Also, GROW has international stocks... keeping in mind that for the last year, global investing has been very hot, and a lot of people have this delusion that the US markets and the global markets are not related (ie, if WE dump, it's OK, I am in INTERNATIONAL funds!). People just woke up to the fact that when we dump, they dump. Are international funds going to be as hot as they were? Dunno.
I think the short interest is more a testament to how beary people were about the market as a whole. While there's not sufficient data to back this up, it may be that watching the short interest on GROW could be a nice indication of market sentiment

. That is, a lot of people expected a crash, and are willing to bet on it. But knowing the market... we also know that the majority are usually wrong.
What's the first thing people do when their money's at risk? GET OUT. What are they getting out of? 'Risky' funds of course first. Most long time investors know a bit more about when to get out, we don't panic like new people. What's risky? A new fund. What's new? A GROW fund.
So, when people think the market will tank, they will dump the stocks dependent on the market first. A canary in a coal mine stock maybe.
I knew the market was going to be OK when GROW went up after the crash, and everything else was still red. SOMEONE believed it wasn't going to keep going down... a lot of someone's or they wouldn't be selling their shorts so early, nor would they be buying it long. Hmm?