The surge in xrp price is not in any way, shape or form solely and exclusively correlated to the spark token airdrop, it's an altseason across the board, almost all top alts have witnessed a considerable increase in prices, them too are appreciating in value due to the spark airdrop? Of course not...

Therefore while spark will lead to more investors buying xrp to benefit from the airdrop post-snapshot and some will dump after the snapshot takes place, I don't think there will be a huge dump that is significant enough to lead to a sudden and steep decline in xrp price, there's over 3 billion xrps held on coinbase alone so go figure, it's not the spark airdrop that will define the use case and utility therfore the value of xrp, it's actually the other way around, xrp gives value to spark and gives it the utility it needs to bridge the XRPL to the Ethereum blockchain.

So not sure if xrp will go up or down post snapshot but if it ever falls I don't think it will be a steep decline, nothing more than any other coin that will eventually witness a healthy correction / adjustment.