Wheat futures surged by their daily price limit again Monday, extending a relentless surge towards all-time highs and fanning fears of a global commodity shock as Russia’s invasion of Ukraine shuts off a crucial source of exports and threatens future production of the key food grain.

Soft red winter wheat for May delivery W00, 7.03% WK22, 7.03% rose 85 cents, the expanded daily price limit, to lock at $12.94 a bushel, a gain of 7%. Wheat has traded up by its daily limit for six consecutive sessions and last week rose more than 40%, for its biggest weekly rise on record.

Wheat is up nearly 68% to date in 2022.

Russia and Ukraine combined account for 25% of global wheat exports, and Ukraine alone for 13% of corn exports, according to analysts at RBC Capital Markets. Concerns about future crop prospects are also fanning gains, analysts said.

“The risk now is that [Ukraine] planting is further compromised. We get more clarity on that topic every week, and thus far it looks problematic,” said David Whitcomb, head of research at Peak Trading Research, a Geneva-based quantitative commodity trading and research company. “How many trucks will be moving about freely in the next 60 days? How many workers available? How much fuel available? Inputs like fertilizer available?”

All-time price records for wheat are also within reach. The record close for a most actively traded contract was set on March 12, 2008, while an all-time intraday high of $13.50 was set on Feb. 27, 2008, according to FactSet data going back to 1984.

Corn futures C00, -2.19% were up 3 cents at $7.5725 a bushel, or 0.4%, and have surged 9.6% in March and 27.6% so far in 2022. Soybeans S00, -0.09%, which aren’t major crops for Russia or Ukraine, have been dragged higher, rising 6 cents Monday, or 0.4%, to $16.665 a bushel, up 1.8% for the month and 24.4% so far in 2022.

The surge in wheat and other grain futures comes alongside record gains last week for oil BRN00, 4.35% CL.1, 2.97% and metals as a result of Russia’s invasion of Ukraine, contributing to a record weekly surge for the S&P GSCI SPGSCI, -3.55%, a commodity index composed of 24 exchange-traded futures contracts across five physical commodities sectors, which rose around 18%.