£10,000 invested in Rolls-Royce shares in the past one year is now worth…

Back in September 2023, Rolls-Royce (LSE: RR.) shares were sitting comfortably at 215p a pop. That was a remarkable price considering the same stock changed hands for just 75p or so 12 months earlier.

At that time, I couldn't buy myself, I believe that any company will find it difficult to regain almost 186% in the next year.

Somehow, I have always been focused on money. Rolls-Royce you have failed to match this form. But still very well done.

Amazing benefits

Using today's share price, I would have made a stunning 119% return if I had bought in September 2023. So, a £10,000 investment would have grown to £21,900. For comparison, the FTSE 100 it increased by only 11% during the same period. And that's a pretty good return considering how much the index has underperformed in recent times.

Is there more to come? At the risk of sounding like a stuck record, I'm not so sure.

A worrying development

An engine failure on a Cathay Pacific flight earlier this week appears to have caused at least some investors to bank a profit. We are seeing more selling pressure today (6 September). This follows the announcement that the European Union Aviation Safety Agency has requested that checks be made on some of the company's engines.

The question that is being asked now is whether this is a one-off issue or something else. If more errors are found, we can expect more flights to be canceled by airlines. This will be a big problem for Rolls-Royce. Simply put, it makes most of its money when the planes are in the air.

Is the stock priced to perfection?

Now, popular songs and benefits would be tolerable to me if it was clear that any problems were solved quickly and the company's valuation was not yet foaming. However, Rolls-Royce shares are currently changing hands at a forecast price-to-earnings (P/E) ratio of 28, according to my data provider. This means that investors are interested in the company's vision. But it also suggests they won't be apathetic if the company disappoints a little.

I might be comparing apples and oranges here but this is similar to what is happening across the pond with it Nvidia. Although the manufacturer's long-term outlook still looks very positive, it seems that near-term expectations have finally come true. And its shares are down 12% in just the last five trading days.

One of my thoughts is whether this week's news could mean that Rolls-Royce's plan to restart its dividend – announced in August – could be delayed. If this happens and a purple sheet of stock comes to a halt as a result, I will not be compensated for sitting patiently and waiting for recovery.

I'm still cautious

With efficient cost cutting and an admirable no-nonsense approach, I think CEO Tufan Erginbilgiç has done an amazing job of turning this company around. I wish my crystal ball was working and forced me to invest one year ago. At the height of the pandemic it would have been even better. Congratulations to whoever did it. No sour grapes here.

But I remain wary of Rolls-Royce shares, albeit for different reasons than before.