As shown by $MUT’s monthly chart:

In the sell off in 2011, the SMA 50 acted as support.

In the sell off in 2015, price got close to, but never tested, the SMA 50 as support.

In the sell off in 2018, price never even got close to the SMA 50.

In the sell off in 2008, the SMA 50 initially acted as support, then that support level failed.

In this sell off, price has fallen straight through the SMA 50 like it wasn’t even there.