It doesn't really mean much that no insider has traded Rolls-Royce Holdings shares in the last quarter. On a brighter note, the transactions over the last year are encouraging. While we have no worries about the insider transactions, we'd be more comfortable if they owned more Rolls-Royce Holdings stock. In addition to knowing about insider transactions going on, it's beneficial to identify the risks facing Rolls-Royce Holdings. Case in point: We've spotted 1 warning sign for Rolls-Royce Holdings you should be aware of.