Stock gains are great, but they don’t necessarily continue forever. Today’s fast rising investment can be tomorrow’s disappointment. As such, it is important for investors to pay attention to what is happening with the stocks they own and be ready to sell when the situation warrants or when the thesis behind an investment changes.

While Warren Buffett’s comment that his favorite holding period with a stock is forever, in reality there comes a time when most investors should sell a holding or risk losing their gains. Worse, a gain could turn into a loss. To protect profits, the best thing investors can do is often to sell a security that they own. Here’s why it’s now time to sell these three hot stocks.

Eli Lilly (LLY)

If you believe in the adage buy the rumor, sell the news, then it’s definitely time to sell the stock of pharmaceutical company Eli Lilly (NYSE:LLY). The U.S. Food and Drug Administration has just approved Eli Lilly’s weight loss drug and obesity treatment, paving the way for billions of dollars in sales. LLY stock has run up 65% on the year in anticipation of the FDA approval, and now looks primed for a pullback. The prescription drug will now be marketed and sold as a weight loss treatment called “Zepbound.”

In time the weight loss medication will help Eli Lilly grow by leaps and bounds. Zepbound is widely expected to be one of the top-selling prescription drugs of all-time. However, as is often the case, investors are selling LLY stock now that the big event, i.e. regulatory approval, has occurred. There are also concerns about Eli Lilly’s ability to meet demand. Pricing for the drug, which Eli Lilly has set at $1,059.87 per dose, is also of concern, as is the fact that insurers don’t currently cover it.

These issues will get worked out in time. For now, investors should hold off on buying LLY stock.

Tesla (TSLA)

The stock of electric-vehicle maker Tesla (NASDAQ:TSLA) has been a bit of a basket case lately. Since mid-October, the stock has fallen 25% only to rebound 14%. Since July, the company’s stock has traded both near $300 and below $200. It’s not uncommon for the share price to move 5% lower or higher in a single trading session. Almost as volatile as the price swings are the price targets on the stock. Currently, the highest analyst forecast on TSLA stock is $380 a share, while the lowest estimate is $53 per share.

All the drama and volatility has been due to the fact that demand for electric vehicles is slowing and Tesla has had to cut the prices on its sedans and SUVs dramatically to help sell them. Some Tesla models have seen their prices lowered by a third. This has negatively impacted Tesla’s earnings and outlook. The company’s third-quarter print was a disaster, with Tesla reporting a 37% decline in its earnings per share (EPS). Operating profit margins came in at 7.6%, down nearly 10 percentage points from a year ago.

Unless investors can stomach volatility over the long-term, it’s time to sell TSLA stock.

Riot Platforms (RIOT)

Crypto has been red hot this year and that has benefitted the stocks of cryptocurrency miners such as Riot Platforms (NASDAQ:RIOT), whose share price is up nearly 200% since January. However, there’s reason to be cautious with both crypto and RIOT stock. Analysts at JPMorgan Chase (NYSE:JPM) recently issued a warning about the current rally in cryptocurrencies, saying that the rise in digital asset prices now looks “overdone.”

Excitement about the potential approval of a Bitcoin (BTC-USD) exchange-traded-fund (ETF) has fueled a strong rally in digital asset prices over the last month. At about $37,000, the price of Bitcoin has risen 38% in the past four weeks and is now up 122% on the year. JPMorgan analysts question the notion that approval of a Bitcoin ETF will attract billions of dollars worth of new capital, saying that it is more likely existing capital will shift from current Bitcoin products to the new ETFs.

JPMorgan also notes that cryptocurrency ETFs already exist in Canada and Europe and have attracted “little interest from investors.” Lastly, JPMorgan says that most bullish tailwinds for the crypto sector are already priced in, and that prices look more likely to fall than rise from current levels. Given that RIOT stock is now up 192% on the year, now might be a good time for shareholders to take profits.

On the date of publication, Joel Baglole held a long position in LLY. The opinions expressed in this article are those of the writer, subject to the InvestorPlace.com Publishing Guidelines.