The prediction market will resolve as "No" (South Africa will not remain a democracy) if, for any year from the present until 2030, South Africa fails to meet all the following conditions:
Freedom House's Freedom in the World Index: South Africa is classified as "Not Free" in the Freedom in the World Index's annual reports. The country must have a combined score of less than 30 out of 100 in any year, with lower scores indicating less freedom.
The Economist Intelligence Unit's (EIU) Democracy Index: South Africa's score in the EIU Democracy Index must be below 6.0 out of 10 in any year, which would categorize the country as a "Hybrid Regime" or an "Authoritarian Regime."
Polity IV Project's Polity Score: South Africa must have a Polity Score of less than +6 in any year in the Polity IV Project data, indicating that the country is either an "Anocracy" leaning towards authoritarianism or an "Autocracy." A score of -10 would represent a "Full Autocracy."
If South Africa does not fail all three of these conditions for any year from the present until 2030, the prediction market will resolve as "Yes" (South Africa will remain a democracy).
Related questions
Polls are showing that the ruling party, the ANC, is losing support and will possibly get less than 50% of the vote in the 2024 election. This will force the ANC into a coallition government with smaller parties, we've already seen examples of this in the Metros of the Gauteng province.
This means that the trend in South Africa is away from centralization of power. If anything South Africa is more likely to be an anarchy between 2024-2029 as national coalltions rise and fall.
@Nostradamnedus It's not a power vacuum. The power is still in parliament. It's just that no individual party will have enough power to control parliament unilaterally.