As the 2018 election period started, the government introduced public posters with a photo of Soros to create hostility in the general public towards him, using statements such as "Soros wants millions of migrants to live in Hungary", and "Soros wants to dismantle the border fence". The government also prepared a three-part law plan called the "Stop Soros package" (which followed other various law changes in the same year, hindering the workings of several international NGOs in Hungary), which would include various steps against NGOs doing volunteer work related to the refugee crisis.
On May 16, 2018, Soros' Open Society Foundations announced they would move its office from Budapest to Berlin, blaming the move on an "increasingly repressive" environment in Hungary.
Soros' opposition to Brexit (in the United Kingdom) led to a front page on the British Conservative supporting newspaper, The Daily Telegraph in February 2018, which was accused of antisemitism for claiming he was involved in a supposed "secret plot" for the country's voters to reverse their decision to leave the European Union. While The Daily Telegraph did not mention Soros is Jewish, his opposition to Britain leaving the European Union had been reported elsewhere in less conspiratorial terms. Stephen Pollard, editor of The Jewish Chronicle, said on Twitter: "The point is that language matters so much and this is exactly the language being used by antisemites here and abroad". In October 2019, Leader of the House of Commons Jacob Rees-Mogg accused Soros of being the "funder-in-chief" of the Remain campaign, and was subsequently accused of anti-Semitism by opposition MPs.
In October 2018, Soros was accused of funding a Central American migrant caravan heading toward America. The theory that Soros was somehow causing Central American migration at the southern US border apparently dates back to late March 2018, however. The October 2018 strain of the theory has been described to combine anti-semitism, anti-immigrant sentiment and "the specter of powerful foreign agents controlling major world events in pursuit of a hidden agenda", connecting Soros and other wealthy individuals of Jewish faith or background to the October caravan. Donald Trump was among those promoting the conspiracy theory. Both Cesar Sayoc, the perpetrator of the October 2018 attempted bombings of prominent Democrats, and Robert Bowers, the perpetrator of the Pittsburgh synagogue shooting, referred to this conspiracy theory on social media before their crimes.
In November 2018, Turkish President Recep Tayyip Erdoğan denounced Soros while speaking about Turkey's political purges, saying: "The person who financed terrorists during the Gezi incidents is already in prison. And who is behind him? The famous Hungarian Jew Soros. This is a man who assigns people to divide nations and shatter them."
A pipe bomb was placed in the mailbox at Soros's Katonah, New York home on October 22, 2018, as part of the October 2018 United States mail bombing attempts. The package was discovered by a caretaker, who removed it and notified authorities. It was photographed and exploded by the FBI, which launched an investigation. For several days afterward, similar bombs were mailed to Hillary Clinton, Barack Obama, and other Democrats and liberals.
On October 26, 2018, Cesar Sayoc was arrested in Aventura, Florida, on suspicion of mailing the bombs. In August 2019, Sayoc was sentenced to 20 years in prison for mailing 16 pipe bombs to 13 victims. None of the devices had exploded.
In 2018, Soros highlighted that Europe faces major challenges related to immigration, austerity, and nations leaving the EU. He holds that Europe is facing an existential crisis, in view of the rise of populism, the refugee crisis and a growing rift between Europe and the United States. Soros has also stated that "the euro has many unresolved problems" which "must not be allowed to destroy the European Union". He advocated replacing the notion of a multi-speed Europe by the aim of a "multi-track Europe" that would allow member states a wider variety of choices.
In October 2018, Soros donated $2 million to the Wikimedia Foundation via the Wikimedia Endowment program.