Those hoping that the stock market pain from President Donald Trumps tariff announcements last week was over are in for a rude awakening this morning. As of the time of this writing, stock markets across the world have gotten hammered, adding to fears of a new so-called economic nuclear war. Heres what you need to know about the latest developments in Trumps tariff trade war and how the markets are reacting.Bill Ackman: Trump tariffs are economic nuclear warOne of the most headline-grabbing pieces of news related to the ongoing stock market crash is comments from billionaire hedge fund manager and Trump supporter Bill Ackman. Yesterday, Ackman took to X to warn that Trumps tariffs, the worst of which are scheduled to go into effect this Wednesday, April 9, are equivalent to economic nuclear war.In a post on X, Ackman said that the tariffs on Americas allies and enemies across the globe mean America is in the process of destroying confidence in our country as a trading partner, as a place to do business, and as a market to invest capital.Ackman suggested that Trump should call a 90-day time out on the tariffs so the administration can negotiate with its trading partners.However, Ackman warned, If, on the other hand, on April 9th we launch economic nuclear war on every country in the world, business investment will grind to a halt, consumers will close their wallets and pocket books, and we will severely damage our reputation with the rest of the world that will take years and potentially decades to rehabilitate.Will Trump and his administration heed Ackmans advice? Thats unknown. But they certainly didnt seem to have similar thoughts over the weekend, when Trumps administration spent much of the time doubling down on the tariffs that are currently sinking Americans retirement savings and already raising the prices American consumers pay for goods.In a post on his social media platform, Truth Social, President Trump boasted that many of the tariffs are already in effect, and a beautiful thing to behold. Trump went on to proclaim that Some day people will realize that Tariffs, for the United States of America, are a very beautiful thing!Markets plunge around the worldagainHowever, outside of Trump and his administration, its unlikely that many Americans feel that the tariffs are a beautiful thing to beholdat least if they have a 401(k) pension or other retirement plans. Thats because, as of the time of this writing, stock markets around the world are crashing yet again, following major crashes on Thursday and Friday of last weekthe two trading days after Trump announced his tariffs on April 2.Today, the third trading day after Trumps tariff announcement, markets in Asia and Europe have already plummeted, according to data from Yahoo Finance. In Japan, the countrys Nikkei 225 stock market fell 7.83% on Monday, and Hong Kongs Hang Seng Index fell a staggering 13.22%. Shanghais SSE Composite Index fell 7.34%.European markets are currently in the middle of their trading day and are also getting hit hard. The United Kingdoms FTSE 100 is currently down 3.62% as of the time of this writing. Frances CAC 40 is down 3.92%, and Germanys DAX Performance Index is down 3.66%.American stock markets are also down in premarket trading, suggesting that U.S. markets are in for another rough session when they open at 9:30 a.m. ET.S&P 500 Futures: down 1.79%Dow Futures: down 1.93%Nasdaq Futures: down 1.95%Big Tech and Big Retail sinkagainGiven that S&P, Dow, and Nasdaq futures are all down as of the time of this writing, it should come as little surprise that major U.S. tech companies and retailers are also seeing their shares sink for the third trading day in a row after Trumps tariffs were announced.Many U.S. tech companies and most U.S. retailers rely on products, parts, or components that come from Asia, which is the region of the world hit hardest by Trumps tariffs. Here is how major tech companies are currently trading as of the time of this writing in premarket trading:Alphabet Inc.(Nasdaq: GOOG): down 1.48%Amazon.com, Inc.(Nasdaq: AMZN): down 2.09%Apple Inc.(Nasdaq: AAPL): down 2.75%Meta Platforms, Inc.(Nasdaq: META): down 2.24%Microsoft Corporation(Nasdaq: MSFT): down 1.61%NVIDIA Corporation(Nasdaq: NVDA): down 3.39%Shopify Inc. (Nasdaq: SHOP): down 5.55%Tesla, Inc.(Nasdaq: TSLA): down 4.84%And here is how major U.S. retailers are currently trading in premarket:RH (NYSE: RH): down 0.47%V.F. Corporation (NYSE: VFC): down 4.93%Five Below, Inc. (Nasdaq: FIVE): down 2.11%Wayfair Inc. (NYSE: W): down 4.91%SharkNinja, Inc. (NYSE: SN): down 1.56%Walmart Inc. (NYSE: WMT): down 1.02%Costco Wholesale Corporation (Nasdaq: COST): down 0.96%Target Corporation (NYSE: TGT): down 2.21%While many of these stocks are seeing low double-digit drops in premarket this morning, keep in mind that most were hammered much, much harder last Thursday and Friday.Now cryptocurrencies are crashing, tooBut its not just stock markets and individual stocks that are falling today. Now cryptocurrencies are being hit fairly hard, too. As of the time of this writing, major digital assets are down, including:Bitcoin: down 6.79% to $77,141.06Ethereum: down 16.28% to $1,495.82Solana: down 15.12% to $100.89Dogecoin: down 14.85% to $0.1398Official Trump: down 14.4% to $7.69Banks say the odds of a global recession are increasingFinally, it should be noted that now a second major investment bank has come out to say that, due to Trumps tariffs, the odds of a new global recession are increasing.Last week, J.P.Morgan upped the odds of a global recession due to Trumps tariffs to 60% (up from 40% before the tariffs were announced).Now, Goldman Sachs has also raised its odds. Pre-Trump tariffs, Goldman Sachs said that there was a 35% chance of a recession. Now Goldman Sachs says that the chance has jumped to 45%, notes Reuters.