The markets have been on a roll recently, but investors need to stay vigilant and not get complacent, Jim Cramer warned his Mad Money viewers Friday. Stocks may have a tough time next week, depending on how the Federal Reserve responds to these changing market conditions.

Cramer's game plan for next week started on Monday with the planned IPO of co-working space provider WeWork. Cramer said this IPO has him nervous, as the deal has been having trouble finding a price low enough to lure investors. IPOs that go bad can take the rest of the market with them.

On Tuesday, we hear from FedEx (FDX - Get Report) , a company that knows more about the global economy than anyone. We will also hear how the cloud is faring from Adobe Systems (ADBE - Get Report) and whether cybersecurity is slowing down when Zscaler (ZS - Get Report) hosts its analyst day.

Also on Tuesday are the latest industrial production and capacity utilization numbers, which will help set the stage on Wednesday when we will hear from the Fed. Weaker numbers on Tuesday will help justify an interest-rate cut on Wednesday.

Rounding out earnings for the week will be General Mills (GIS - Get Report) on Wednesday and Darden Restaurants (DRI - Get Report) on Thursday. Cramer said he'll be listening to both companies. On Friday, everyone will be waiting to see if President Trump tweets anything regarding trade -- tweets which affect the stock market.

Speaking of Trade and Tariffs...

Before you buy any stock, you need to play a little game, Cramer told viewers. That game is "hostage or not" and it will tell you if your company is hostage to the trade war with China or whether it can be safely bought.

Caterpillar (CAT - Get Report) is not technically hostage to China, Cramer explained, as it derives less than 5% of its revenues from there, but the stock trades on trade news, making it a hostage. The same with Deere & Company (DE - Get Report) , as all agriculture is now tied to China; 3M (MMM - Get Report) and Nvidia (NVDA - Get Report)  , as most semiconductors are also tied to tariffs and trade.

Some companies that are not hostage include Bank of America (BAC - Get Report) and Wells Fargo (WFC - Get Report) , both of which are domestic banks. Splunk (SPLK - Get Report) , Workday (WDAY - Get Report)  , and the cloud stocks also are not hostage to the global economy because they're driven by secular trends.

Finally there are companies like apparel maker PVH (PVH - Get Report) , which are most definitely hostage to trade until the company can product most, if not all, of its products outside of China. 

Cramer and the AAP team are are adding to a pharmaceutical name in the portfolio, while taking gains in a semiconductor stock. Find out what they're telling their investment club members and get in on the conversation with a free trial subscription to Action Alerts Plus.

Know Your IPO

In his "Know Your IPO" segment, Cramer examined the stock of SmileDirectClub (SDC) , which was priced at $23 a share, only to open at $20.55 before falling to lows of $16.67.

SmileDirect competes with Align Technologies (ALGN - Get Report) in the invisible orthodontics space, But unlike Align, which requires regular visits to your dentist, SmileDirect allows for at-home impressions of your teeth and virtual check-ins with a dental provider.

Cramer said he likes SmileDirect's accelerating revenues, rising average selling price and the fact the company is trending toward profitability. On the downside however, the stock is expensive at 8.5 times sales at a time when the market values profits, not revenues. He was also worried, as is most of Wall Street, that increased competition may put a damper on profits for both SmileDirect and Align.

In the end, Cramer said he likes SmileDirect, but only if shares fall back to their lows below $16 a share. 

On Real Money, Cramer keys in on the companies and CEOs he knows best. Get more of his insights with a free trial subscription to Real Money.

Cramer Does His Homework

In his "Homework" segment, Cramer followed up on a few biotech stocks that had stumped him during earlier shows. He said that biotech is a tricky business and is always speculative. Investors should never gamble with retirement savings, Cramer urged, and only invest with discretionary funds.

Cramer said that Cymabay Therapeutics (CBAY) illustrates the potential pitfalls of early-stage biotech. The company had disappointing Phase II trials and the stock plummeted. Iovance Biotherapeutics (IOVA) , on the other hand, is worth speculating on, as the company's cancer treatments are promising, Cramer said.

Cramer's big recommendations came with Arrowhead Pharmaceuticals (ARWR - Get Report) and Regenxbio (RGNX - Get Report) , both of which have multiple drugs in development and strong partners to help them cross the finish line.

As for Krystal Biotech (KRYS) , Cramer was less confident, as the company has a higher focus, with fewer chances to win and lacks the support of a bigger partner.

Continuing his "Homework" segment, Cramer followed up on three more stocks he needed to study. He said that Accelerate Diagnostics (AXDX - Get Report) has failed to deliver on its promises and he cannot recommend it; and TTM Technologies (TTMI - Get Report) is too risky given the company's exposure to China and the trade wars. He was bullish on Medpace Holdings (MEDP - Get Report) however, as the contract research business remains a lucrative one.

Lightning Round

In the Lightning Round, Cramer was bullish on Alcon (ALC) and Novartis AG (NVS - Get Report) .

Cramer was bearish on Trex (TREX - Get Report) , Enphase Energy (ENPH - Get Report) , Rite Aid (RAD - Get Report) and Tallgrass Energy (TGE - Get Report) .

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At the time of publication, Cramer's Action Alerts PLUS had a position in CAT, NVDA, NVS.