It’s a really complex topic, and if anyone had the exact answer, they’d make a fortune, of course. Personally, unless there are extremely strong fundamental industry changes, I think spreads like this are generally under utilized. Everyone always tends to say “it’s different this time” until it’s not.
But of course I’ve been waiting for this particular spread to reverse for over a decade now haha. as far as fundamental reasons, people may claim this spread is no longer viable due to the decline of platinum automotive catalysts, however, this spread predates the use of auto catalysts. It is based more on the relative cost of mining each metal which has not changed. You could go into other minor fundamentals for days, but ultimately, I feel the cost of mining will eventually cause the platinum gold spread to return to its historic level. just my opinion.