The above button links to Coinbase. Yahoo Finance is not a broker-dealer or investment adviser and does not offer securities or cryptocurrencies for sale or facilitate trading. Coinbase pays us for certain activity generated through this link. Prices displayed are informational.

Is SIG a good stock to buy? We came across a bearish thesis on Signet Jewelers Limited on Valueinvestorsclub.com by greenshoes93. In this article, we will summarize the bears’ thesis on SIG. Signet Jewelers Limited's share was trading at $85.00 as of April 29th. SIG’s trailing and forward P/E were 12.30 and 8.02 respectively according to Yahoo Finance.

Signet Jewelers Limited (SIG) is a leading U.S. specialty jewellery retailer with over 2,700 stores and a portfolio of brands including Kay, Zales, and Jared, but faces mounting structural challenges driven by the rapid adoption of lab-grown diamonds (LGDs). Industry dynamics are shifting as LGDs, produced primarily in India and China through scalable and low-cost processes, have significantly reduced diamond prices, with stones now available for under $100 per carat.

Read More: 15 AI Stocks That Are Quietly Making Investors Rich

Read More: Undervalued AI Stock Poised For Massive Gains: 10000% Upside Potential

While this has initially supported Signet’s average transaction values through customer “trade-up” to larger stones, this benefit is expected to plateau as consumer demand for size caps near 2–3 carats. As LGD prices continue to decline, gross profit dollars per unit are likely to compress, particularly in bridal, which represents roughly half of revenue. Although LGDs currently offer higher margins, sustained price deflation combined with limited volume growth mirrors semiconductor-like pricing pressure without sufficient offset from demand expansion.

Additionally, rising gold prices are materially increasing input costs, especially in fashion jewelry where gold constitutes a larger share of the bill of materials, further pressuring margins. Signet’s large fixed-cost store base and consultative sales model limit its ability to reduce expenses, while its lower-end consumer focus faces heightened competition from digitally native, direct-to-consumer entrants leveraging LGDs.

Despite cost-cutting initiatives, the company’s revenue is projected to decline as natural diamonds are cannibalized and LGD growth normalizes. With earnings expected to deteriorate over the next several years, the current valuation appears overstated, presenting a compelling downside case.

Previously, we covered a bullish thesis on Signet Jewelers Limited SIG by Elliot in March 2025, which highlighted its attractive valuation, strong free cash flow generation, aggressive share buybacks, and restructuring initiatives to drive efficiency and growth. SIG's stock price has appreciated by approximately 50.98% since our coverage. greenshoes93 shares a contrarian view but emphasizes on structural risks from lab-grown diamonds, margin compression, and long-term earnings decline.

Signet Jewelers Limited is not on our list of the 40 Most Popular Stocks Among Hedge Funds. As per our database, 35 hedge fund portfolios held SIG at the end of the fourth quarter which was 33 in the previous quarter. While we acknowledge the risk and potential of SIG as an investment, our conviction lies in the belief that some AI stocks hold greater promise for delivering higher returns and doing so within a shorter time frame. If you are looking for an AI stock that is more promising than SIG and that has 10,000% upside potential, check out our report about this cheapest AI stock.

Disclosure: None.